A swap is a social event to share with one another.
The blocks should be usable, but you should expect them to come from both ends of the skill spectrum. You are going to get someone's best effort that is not as good as your poor effort. I have been that hard worker, poor product person.
Swaps are Lottery participation activities. You pays your money, you laughs, you cries, you makes new friends, and you has a lotta fun.
If you don't have that spirit, try to find it, or keep yourself happy and do not swap.
I really, truly do not expect to have a well designed quilt when I finish a swap, I expect to have laughs, smiles, and fun. But, it will BE a QUILT.
The ugliest quilt I ever own may be the funky chicken throw, or it may be the best. I don't know yet, because I have not had time to design the layout, sashing, and borders. But man! I can't stop talking about those crazy chickens. The effort of the swap already paid for itself, and I do not even have a quilt yet.
Good luck, have fun.
Hugz and smilez to each and everyone of you.
Aardie.