Here is an idea. Smeone could do a run since I don't own the game and I hate emu
Rules: Glitches are allowed expect for credits warp Time starts upon entering a new save pipe and ends and the 3rd hit of wario VBA is banned
Such a route exists (for a TAS). For it to actually be faster than the normal Any% Glitchless route, it would require a number of frame perfect tricks, including ones that runners generally do not practice. Basically, it won't happen, and it would probably be slower in the end due to the runner having to attempt the tricks numerous times.
^This. The frustration factor of such a route would probably be very high.
The 2 main exploits would be the pipe glitch and the checkpoint bell glitch. The latter would probably only be used in the Space Zone boss level. Setting it up is a time investment of ~30 seconds. Performing it is not an easy task because of its frame-perfect nature. If you miss it it takes another 30 seconds (plus the time for the soft-reset) to attempt.
The pipe glitch (including the pipe death glitch) would be used in several places. Possible levels to set it up quickly are Macro Zone 1 and Pumpkin Zone 1. You would beat those levels, perform the pipe glitch and carry the glitched state to other levels. You'd then proceed to fall through the floor in those levels and find a trigger to complete it quickly. Consistent triggers to finish levels are rare and success is not guaranteed. Having to set up the pipe glitch again after failing it would take a variable amount of time, depending on the distance between the levels (setup level & execution level). Failing it only once can already negate the possible time save compared to beating the level normally, though. On top of that, only a certain number of levels even have an accessible out-of-bounds area where you can hunt for level end triggers - in many others you just drop into an empty copy of the original level without the possibility to beat it quickly.
To sum it all up: such a route is certainly possible, but to me it does not sound fun to run. I invite you to try it out yourself. Not owning the game is hardly an excuse, since you can pick it up for $5 pretty much everywhere (includes some trial and error, because you need version 1.0 of the game).
Another glitch that could save time is the bubble glitch in Wario's Castle. However, it's only been done by TAS as far as I know (I've attempted it RTA, but never successfully).
Any% low glitch is a stupid category because of the 1 frame tricks involved (Pipe death, checkpoint bell bug). You don't want to do a 1 frame trick 10 minutes into a run. Back in the day, I did low glitch runs until we all decided to make it glitchless to get rid of the 1 frame tricks mess.
HOWEVER, it is not a bad idea to just add it now as its own category. Perhaps it will rise in popularity and beasts like oh_deer will take it apart.
In fact, I've already started to discuss the matter of a few more miscellaneous categories on these leaderboards here. This particular one would most likely stay empty, though. As mugg can probably attest from experience, it takes a high level of knowledge and execution to even complete a run of this (faster than the Glitchless version). There is currently no high-level runner (nor anyone else) interested in running this. If someone did put in some work, finished a run and contacted me about making it an official (miscellaneous) category, I'd be happy to follow that suggestion.
Funny how things can change: https://www.speedrun.com/sml2/full_game#Beat_Wario °--°
[quote=mugg1991]Back in the day, I did low glitch runs[/quote] Any chance you still have a recording you want to add to the leaderboard?