hey, a little late in responding to this but i actually recently tried testing this out! it's a mostly good solution, but there are some minor limitations with it.

i cut the fps in half from 144 to 72fps and then doubled the bounce, animation speed, and frequencies for all the sprites to offset it. it solves the issue (almost) completely! however, a few sprites i had set with a fast "shaking effect" frequency that were already at the maximum 0.1 value are unfortunately still slower as i am unable to double them to adjust for the new fps value.

it is a decent work-around, but it would be great to have a fix for this in the future! i understand it is likely not a priority and there are issues with potentially breaking existing avatars, but it'd be really nice to fully optimize and customize the app's performance without having to fuddle around too much. i'd gladly go through the trouble of fixing my avatar for this to work! the difference between running 144fps vs 72fps is a moderately less amount of CPU/GPU usage for me, and most folks stream at 60fps maximum anyways.

the current tutorial doc lists changing the fps in the .pngtp file as a valid option, but with its current state i just worry folks may end up confused like i was. adding a minor note in the doc noting  and describing the issue would be a good idea to avoid any further confusion, at least for the time being.

either way, i hope the feedback helps! (also hope i'm didn't come across as too nit-picky!) thanks again for the responses and suggestions! :)