On the topic of tile size. I need to quote myself:
VTs are essentially unbounded in size, further it is difficult to predict how large a decoded tile will be. A single rogue tile could potentially use up all available memory. Besides offering a gigantic attack surface for DoS attacks, this creates issues with quite legit services, see Mapillary V4 issues #1435 .
See: MVT issues/enhancements · Issue #1396 · MarcusWolschon/osmeditor4android · GitHub