Significant Lag. Making me sad.

Hi. My beloved and trusty Fresco has become extremely frustrating. About every 5 minutes, the app stops working for about 10-15sec. It doesn't "recover" and catch up with the brush strokes I've made during that time, it just like won't respond for a bit. Since I mostly use pixel brushes, that's when it's most evident and frustrating and very interruptive to say the least.  Couple things...

This happened regardless if I'm online or off. 

I'm using an IPad Pro 12.9 3rd Gen (late 2018) and using Apple Pencil. 

I have over 200GB free space. 

Admittedly, the file is large: 6.25in x 10.125in at 600ppi. (3975 x 6075) Need it for professional quality. 

It's file size is around 350mb. Which is actually nothing: my last piece was the same pixel size as above and 900mb, and it never once lagged. It's smooth like butter, (I opened it up today and played around on it to be sure.) BUT, that file had around 30 layers. My current file in which this issue is occurring (again, around 350mb) has about 65 layers. All of the layers for both docs are pixel layers. 

Could the presence of more layers be more draining and create lag more so then a file that is double the MB?

 Would love thoughts, I'm getting a bit frustrated.