first

Like tk said, sadly it is not available through GOG anymore :c now the patches are clogged with two broken version of 1.5, an acceptable version of 1.5, and two version of 1.4. If you wanna downpatch to 1221 you'll either need to own the game on Steam, or message GOG support and maybe they'll give you access to 1221

Hardfall cancels can also be more easily found on shorter categories (see: current patch 4ms)

Yeah, both hardfall cancels and damage tanks to avoid boss stuns are known - it's very nice that you found them yourself, however! Always good to be on the lookout for new things

This has been proposed before, more than once. Category extensions/meme runs aren't just run based on the concept, but also on what interesting movement/fights/etc they could provide. Die%/Death%/other names it's been given before would literally be breaking a couple of doors at King's Pass and waiting for the crawlid to hit you enough times