pretty sure this is known

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

You're probably looking at old runs. Look at Onmiwe's run or my run on the current patch leaderboards, we both do it right after king's pass.

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