Maximum # of layers in Animate?

Is there a maximum limit on layers in an Animate "Character Animation" file or am I doing this wrong? I have a 60 second animation with 100+ objects, and so I have 85 layers so far. Each time I add a character (a Symbol) that will move, I create a new layer. It's going to be 4 mins, so I'll have 300 or more moving symbols by the end, on ~300 layers. Is that the best way or should I be re-using layers, with symbols that appear later on being put on a now unused layer? Or failing that, is there a way to collapse previous layer groups while you're working on newer ones? Thanks

Eventually I want to put this on YouTube with music, so - 2nd question - what's the best format to export this video in? Or do I need to use a different Adobe product for that? Thx.

Using Animate v21.0.3 on a Mac Mini M1 OS11.2