Limiting S2 Cell Grids and Fill Covered Cell Tweak

[Jebula999]

Heya,

When showing S2 (Level 15) Cells for 9x9, a limit is reached, and performance drops.
https://i.imgur.com/9KLLpAL.png

Is it possible to do something similar to how RDMTools handles 9x9's by only highlighting the 9x9 area each circle covers?
https://i.imgur.com/fnUNMxQ.png

Most 9x9 Bootstrapping will generally be for larger areas, so this issue will most likely be quite common, and the visualization of each S15 cell in a 9x9 is likely not needed.

Second to that, is the filling of covered cells.

Would it not be better If the fill was persistant?
Currently, the cells are only filled when hovering over a circle.
It might be better if the fill is persistent when using the 9x9 bootstrap.