I accidentally knocked one loose when i first got it, so I removed both and made sure there was no monokote overlapping into the root section of the tip (i.e. in the glue joint). I then laterally balanced the model using a little piece of lead sheet. After determining the appropriate amount of lead needed to balance the wings, I then carved a slot into the tip section of the lighter wing and slid the weight in and CA'd it in place . I then glued using 20 min epoxy holding the tips in place with some blue masking tape. After it set I removed the masking tape and sealed it with clear wing tape. I have semi-cartwheeled it on the tips on a very windy day and they have held fine. The idea with the dowels should work fine. Perhaps you can use some CF rods a dowels and then tape in place.