Hi PJ. Haven't seen you around for a while.
I already found out that glitch
two years ago (although I never made it public). I'll tell you what I know so far.
- I came to the same conclusion as you, that the Wily Machine can be quick killed with this method (but not Wily Capsule, since it doesn't have a hitbox).
- I disassembled how Rush Search works. Rush Search has three random components. One is the item to be dug up, one is the first Rush delay (wag-tail animation) and the last one is the second Rush delay (digging animation). Note the last one does not apply when digging up important items. There is a 3/32, 3/32, 1/32, and 1/32 chance of digging up small life energy, small weapon energy, large life energy, and large weapon energy, respectively. So the chances of pulling this trick off for the Wily Machine is only 1/4.
- Using it on the Cloud Proto visit saves time, if it works. It is also possible to use on the Turbo Proto visit but is difficult to do and unnecessary because there is a full Turbo Proto visit skip which is much faster and isn't random (you have to enter the room by jumping and then exit the room while touching the ground at the same time).
- As you already found, you can use it to get the Proto Shield while Proto Man is talking. With Shade Man already done you can then leave the level. According to my calculations, it is now faster in a TAS to do Shade Man first, quick kill Turbo Man then revisit Shade Man's stage for the Proto Shield.
- For the Bass scene in Shade Man's stage, if Rush Search has very small delay and digs up a small life/weapon energy, you can save a small amount of time here. In 100% you get a shot at this for free because you need Rush Search three rooms before that for the Energy Balancer.
- I couldn't find other places where Rush Search worked.
The Rush Search before the Proto door in Shade Man is something I never found before though, so thanks for that (by the way, you need to hold left while going through the door for it to work). It definitely saves time in a TAS. However this trick doesn't seem to work for any other door.
I've looked at 100% for a while because there are a lot of possible improvements (and not just because of Rush Search glitches). Here is the
test run I made two years ago (requires snes9x 1.51 v7); don't know whether it helps or not.