So after looking at the Resources page for Scratchnapped , I tested this offshoot of Phosphorus called Forkphorus which also it tends to run Scratch games more stable than on the Scratch website or via direct html.

Should future runs on Forkphorus/Phosphorus, like for Scratchnapped , be submitted as emulator? Just wondering.

https://www.speedrun.com/scratchnapped/resources

Nice :) , I would assume you would check the emulator box for it.