During my mobile playthrough. Contraptions that emits lights degrades my fps and later chapter's environment, it goes worse even when I had to fought the second boss with low as 19fps(even though I had 8gb ram) I'm deadass serious. I had this problem since chapter 4 release because back then, it was supposed to be run smoothly before chapter 4.
Here's the screenshot of the lowest fps(and before he swings)
5 lawnmowers, 1 moonlight sensor w/ starshard, and 1 glowstone and that's the rest at Halloween(the only map that's most fps for me)
Also lastly here from what you ask from first(am not an expert of any of these)
I can show you more gameplay problems(only mobile for now) if you want to. Just ask me
tbh am literally looking for other options to lower the graphics or something and all I got is these