Currently every limit of Pico-8 is kinda rigid, but how about it: You can adjust these limits at the cost of the other ones. E.g. you need bigger map, but don't use much of sound or code? You can increase map at the cost of code space/sound space. Alternatively you need more code but not use much sounds? Decrease sound space, increase code space.

Of course default split would be as it is now.

In terms of storing data, it's possible to do this with cstore() and reload(), but it's currently quite awkward. The next couple of updates I want to improve the workflow for handling data and copying data between carts, which should be useful for custom tools like the vector drawing program. The general approach will be to use the editor as usual, but then write code to do custom bank switching or to render maps larger than 128x64.

In earlier versions it was also possible to store data in the unused portion of code space, which I hope to resurrect but it's a little complicated by the new compressed code scheme.

Hm. Though I'd love if editors would support bank switching, with a field where map/sound/gfx data would be saved (start of bank). With defaults compliant with current memory layout.

Also any news on these compression methods you've posted about sometime ago so we can compress it? When it will make it into the api?

//edit: I mean this thing: https://www.lexaloffle.com/bbs/?pid=11383&tid=2092

if you want to get really ambitious... http://banjokazooie.wikia.com/wiki/Stop_'n'_Swop