do you just put a thin layer of CA in and let it dry or do you put the CA in and then insert the set screw and let the glue dry around it?
I'm assuming you need to harden the balsa where a screw will be inserted.
To answer this part of your question, insert the screw, remove the screw, apply THIN CA to the hole. Let the CA
fully cure before re-inserting the screw or you'll never get it out later if you have to.