Okay, I did some testing, and was unable to replicate this glitch using any other strange states, like while being inside Kirby or Dedede from their Inhale move, being bitten by Wario, or Flame Choked by Ganondorf. I also tried if it worked during shield jump state or standing shield stun, to no avail. Looks like only Yoshi's Egg Lay will do the trick!
Additionally, the glitch will happen with any Art, not just Jump, and the glitch will have the same effects.
With Hyper Monado Arts, the effect is not exactly the same, but very similar, with kill ranges differing by only about 3%.
As for the buffs, I've come to call this state "Super Smash" Shulk, because it's mostly really good for killing, since it increases knockback, and increases damage (which in turn, also increases knockback). There are minor ground speed and jump height buffs, but the only real mobility buff I find useful is the (slightly) increased air speed and (actually fairly well buffed) falling speed, but even so, they're not as useful as actual Jump or Speed Art buffs. Additionally, there is knockback taken reduction as well, so that's good (there is a damage taken nerf, but with lessened knockback taken, it doesn't matter as much).
Overall, it's a good state mainly because there aren't any nerfs, aside from the damage taken increase, and it lasts (seemingly) indefinitely. However, combo ability with it is low due to increased knockback, and the mobility buffs don't quite make up for the increased knockback. Like I said, though, good for killing.
While I would love to have this state at my disposal in singles play, honestly, it's basically only good because of the buffs without nerfs. All the regular Monado Arts are better than this at what they do, especially Jump and Speed, very much so. Truthfully, if I had to jump through hoops to get this in singles, or even doubles, it's not really worth it. I very much enjoy the normal Monado Arts, and I don't think finding a way to do this on command would be the Holy Grail of Shulkdom, just a good option if you can do it practically.
Additionally, it has another interesting effect: the endlag (and perhaps even the second slash attack animation itself) on Air Slash is played at a much faster speed, possibly 2 times as fast, making it safer: Shulk starts falling almost immediately.
I also felt like aerial landing lag was slower than usual, but this is likely my imagination (or does Jump Art reduce landing lag? I don't think it does, but maybe I'm just hitting the ground faster due to the increased fast-falling speed... maybe preventing autocanceling... hmm...).
I wanna hear from shulk mains tho, Would you rather have this passive buff or prefer to use all 5 Monado's interchangeably?
To reinstate simply: I would still prefer the 5 regular Monado Arts, because the effects are better, they are switchable, and don't require jumping through hoops to get.