I am with Nappy on this regarding Snake's potiential. I worked with SuSa regarding grabs and releases. Trust me, there is not a whole lot room for improvement that I can see from that area. I am not really sure what you mean to take advantage of, but from all the testing I did and helped out on, there simply is not enough concrete merit in the uses of releases. First off, Snake can really only 100% combo his attacks into air releases on ~11 people (I forget the exact number). Of even that number, most are only comboed by DACUS or dash attack. What advantage is there in that when you could easily get more damage through a tech chase? The only advantage to a grab -> dash attack for the most part is that it could kill people if they ever got to high enough percents and it could be a 100% method to kill them. But the kill percentage is too high for it to me more practical. The rest are merely match-up advantages that we can take advantage on in the rare case. Which is basically Falco, Ness, Lucas and Wario for the most part. In every other case, the releases are outperformed by the idea of techchases.
Unless you are referring to techchases from grabs, then I agree with you UL wholeheartedly. I believe the ability for Snake to decimate the opponent through tech chases has been there forever, but no one has ever had the skill enough to follow through on it. Me and SuSa, along with a number of others found that there are a number of characters who is should be fairly easy to tech chase due to the size of their rolls. A number of characters appear to be impossible to techchase unless you get the read right. Mostly because the speed at which they roll along with the distance makes it difficult to do on reaction. Wario, Lucario, Snake, etc. were examples of this. I believe it was even impossible to regrab Snake's forward roll even if you predicted it because it was so long. (Although, it was never 100% confirmed, but everything pointed that way). But anyway, the potiential with the techchase is certainly untapped to its fullest since it could potiential affect probably over half the cast with the right amount of effort put in.
In other regards, I do not think Snake has any room for improvement. He has great tools as it is, but they are all related to how well the human player can utilize them. So, an unprecedeted tech or overall strategy is not likely to ever happen anymore. It will all boil down to who is in essence a great player enough to apply Snake's tools in the right way given the scenario. But, that is all related to player skill, not character development in my opinion.