I'd be in! My patchwork skills aren't very advanced but i'd love the challenge to improve them.
I was in a quilt block exchange group once but every one got a yard of fabric and you made 12 of the same block for the other twelve quilters :O yes, I got a lot better at piecing, but it was exhausting tbh. Plus I ended up with so many sets featuring a fabric I didn't pick- ended up giving those to a quilt group that made quilts for hospice care. They loved them, I loved passing them on!
Sewing just one block per fat quarter sounds MUCH more manageable.
The minimum block size could be decided by the fabric buyer? 12.5 inch Square is a common size. Or 6.5 inch blocks, but you make 2-4 of them.