Thank you for your thorough response, I really appreciate that.
I agree with all your points:
1. The balance isn't perfect, especially at the start, where a bit of bad luck can fill up your board quite quickly, and it's not that hard to build a mechanism that prevents it.
2. The last theme implementation of scaling I wanted to add is to be able to combine 2/4 elements into a larger tile of the same element (1x2 or 2x2 tile). Code-wise it demanded many changes which I couldn't do in time for the jam, but it was in mind.
Glad you enjoyed!