I tried your repro case, and it behaves the same way in 1.9.3.
Did you experience a regression between versions?
The way the cache size is calculated, is a “good guess”. As the font has “all characters” set, we don’t want to create a possibly gigantic texture.
So the solution is the recommended one, if you know you need more cache space, you set the cache size explicitly.
So for now, unless you can find a regression, I will mark this as “works as intended”.
I have updated to 1.9.4 and I get this warning in the console:
WARNING:GAMESYS: Material /builtins/materials/tile_map.materialc has specified a vertex constant named 'world', but it does not exist or isn't used in any of the shaders.
I see the following constants indeed in the built-ins material: