You can toggle categories in the WR history statistics. Click on the category name or the box next to it and it will be crossed out and removed from the graph. (edit: learning this is broken for some people, apologies)
If your cascade exits are somewhat consistent, you can do DSTA. with 6:10 exits you would probably want to set the time to 1:52 with a -55 to -50 offset. This is a very long time to wait for a reset so I wouldn't recommend it, but once you get sub-6 cascade exits it's going to be much quicker.
It already exists as a Low% category, it would likely never be a Category Extension unless there was significant interest in it. If you would like to join the Low% discord server, you can do that here: https://discord.gg/qkWtmcK
(in the optimal 1.3 route) that also requires you to complete wooded and go through the painting in lake, so that adds most of sand, all of wooded, and a small chunk of lake in exchange for the crc. World record is not possible on 1.3 because of this
Timing the load itself is going to be impossible, but you can approximate by timing from fadeout to fadein.
You can use practice mod on emulator but unless you have a really nice pc, it won't run well and there's no point in using it to practice. The 1970 date is part of the mod. If you want to do it on your switch you will have to mod it.
both IP clip and IP skip are options to skip it until peace, IP clip being the easier option by far
As KilleDragon said, the camera is locked and you need to unlock it to progress, and the fastest way to do that is to warp to it in lake, and to die after collecting it in luncheon. In Mushroom there's a strat that is faster, but it is extremely difficult and isn't done RTA (yet) so the fastest way is to capture the binoculars (so you can warp sooner) and warp to the checkpoint.
that tower can also be completely skipped, and you can come back to it later when the ice is gone (and there's a wire to the top)
it does give you a little bit of height, but it is cancelled out by the time the animation ends
That's not true drew, BP does races with people quite often, and he's going for wr
Join the speedrunning discord and look at the pinned messages in the All Moons chat, there's more than one route to choose from.
make sure your cartridge isn't in the switch when you initialize, and turn off automatic updates before you put it in