Misuko, I gave you the benefit of the doubt, I figured perhaps you were referring to this:
http://smashboards.com/showthread.php?t=164436
I even retested in training for 20 minutes to make sure I didn't miss it the first time I tested all of Olimar's moves. However I can assure you there is nothing special or significant about jumping and Whistling at the same time. The game allows you to jump and use the move at the same time, that is true, same as it is true with SideB Latch. However, this is not any more significant than any timing that you use whistle armor frames to take a hit with. Therefore it is as I described it above, neither new nor a revolutionary new use of old, not even a new perspective.
As for the situation you offered, I'll break it down gladly. You must have a jump in order to do this move. So if your on the stage, no jumps used, and someone is attacking you with a large hit box, you can Shield, Dodge, Roll, or Rising SAF. Only one option results in you taking damage, however 3, potentially all 4 depending on lag, offer opportunities to hit your opponent. The rising SAF only offers a couple aerial options, where the rest have the wider variety of standing ground options. Simply standing on the ground was not your primary intention though I understand that, just covering all situations, on to the next. Your in the air, second jump remaining, above the stage still, and your opponents coming at you with a huge hit box. Now here there are fewer options, jump, air dodge, normal SAF and rising SAF. Jumping doesn't necessarily remedy the situation, it only delays it in hopes your opponent cannot pressure you coming down from that jump, depending on the situation a viable option, sometimes delaying the inevitable you'll end up with just the other two options next time. Normal SAF you take the damage and continue falling, perhaps able to attack, only would really do this to get a good open window for a strong KO move. Rising SAF, it puts you above from where you were, jumping through the attack. If your opponent happens to be just as high in the air as you, or above you, this is not a bad spot to be, ideally you can take the damage and attack back, trade hits but because yours had knock back you'd have momentum. However they can very simply air dodge to avoid the attack, and suddenly your above them again, a bad spot for olimar to be. Now the air dodge, you avoid the attack, and keep falling in relative positions to where you were initially, unless he was jumping up and you falling down, in which case your below him, which is exactly where you want to be, and you didn't take any damage. Now before you start jumping all over this, I have not forgotten the point of your explanation of when to use it, against what you call long disjointed hit boxes. In theory these hit boxes are so long that you can't air dodge through them. The only attacks you can't air dodge through are multi hit attacks. Interestingly enough, you can't Whistle Armor through them either, because they last longer than the SAF. An air dodge offers more protection in any situation where you are above the stage save 1, and that is when your being attacked right as you land on the stage. To this there are plenty of answers, first off, why are you DIing into him on the stage, surely you can DI away from him. There is no harm to landing safely on the ledge, having DIed away from your opponent and away from the stage if the alternative was DIing straight into him in blind hope you land safely, that is just ignorance. So we come to what is most likely the only time that your suggested new discovery would apply to, in the air not above the stage. The options here are the same as above the stage, however add UpB. Rather than go through every possible reason to jump in recovery, I'll just mention that you can jump over your opponent to attempt to land on the stage, not a generally good idea, only suggested if you are very high above the stage yet not over it, in which case recovery isn't much a threat. Moving on to if your parallel to the stage, as I feel this is where your arguing hardest for your rising SAF. Yes, you could jump onto the stage taking the hit and resulting in a poorly spaced neutral setting near the edge. Not the worst option, missing the stage and dying certainly is worse, but i feel theres better ones. Now as mentioned earlier, you could jump and air dodge, it'll work its way just as well through any attack, same result, just no damage. However let me offer a better alternative still. Say you have this extra jump, but rather than use it right then, you avoid your opponents attack first, and then jump and grab the ledge, potentially setting you up to ledge guard or even get a ledge hog kill. There is no rule that you must immediately get onto the stage as soon as possible, you can keep your distance from your opponent, and the stage if necessary, dropping below the height that it is safe to ledge guard at, then jump up from this lower, safer position to the ledge/stage. By staying far enough out from the stage until you are at a difficult height below the stage, you effectively protect your own recovery as you are incredibly difficult to hit in that off/below the stage position. Certainly, any long disjointed hit box that comes swinging your way will last so long, that even if he is to connect through an air dodge, your opponent will surely die as well, those moves have lag because they are so long, and your not far from the bottom KO wall compared to normal situations. In conclusion, because of how effectively protected your recovery is when you are below the stage level, any time you have a second jump it is much more effective to simply drop below and jump up to the ledge rather than approaching parallel jumping in a position much more open to your opponents.
Don't get me wrong, there are certainly situations where whistle SAF are of great use, perhaps you have no jumps left and cannot recover should you be hit, but if you air dodge you'll be too far from the ledge to grab it with UpB, a WAC there is a life saver, and is the perfect application of the technique. Any time you have a jump and are threatened however, there are more safe and efficient options available. Now for the sake of simplicity I didn't even mention the fact that all 4 directional aerials of Olimar's are disjointed, meaning that it would be a matter of priority that Olimar does fairly well in, especially in the air. If you still feel I don't have a clue what i'm talking about and that there is some far off hypothetical situation this may be the best option, I'm all for your attempts at explaining it and will approach it as open minded as possible. However there is certainly no extraordinary characteristic to jumping and WACing at the same time, so at the very least its not a new discovery, simply an argument for a potential best option in a specific situation. Any non momentum changing B move can be done simultaneously while jumping, Olimar can latch as well for instance. If you have a better guide that you think would help clarify by all means I'll check it out, but if you think I'm the only one who considers this post "bad" (apart from the comic relief now offered to others by our argument) then I think your being a tad blinded attempting to defend something you stumbled upon and got caught up thinking was really new and interesting.
-True