Lets say I have a blockgrid defined with 0-infinity blocks allowed. There are 3 block types A, B, and C. Is it possible to configure the grid such that You can have as many of A and B as you want, but only one copy of C?

I believe you are able do this with areas, so you could make a layout block containing an area and then go from there https://cdn.discordapp.com/attachments/1295460402854891700/1295631839213654086/image.png?ex=670f5aae&is=670e092e&hm=55d156f6703d8c62743919a663d0b338bbdffeb8f3724bc1bf553a3111912878&