RE: Wing Bolt Solutions
Oh, I should mention.................
It's quite easy to tap out installed blind nuts in most ARFs. Of course, you need a bolt that fits, but you thread it into the blind nut and then tap it. Look first to see if the nut has been glued, but they usually aren't. If it has been, then go ahead and tap away. The glue usually doesn't hold. I've yet to encounter any that were glued securely at the wing hold-down. Firewall nuts usually are glued almost securely. The thick glue most often seen isn't epoxy and usually hasn't penetrated much, especially on ply.
In a lot of ARFs, the bolt/nut is smaller than 1/4-20 and I've been able to thread the existing holes for 1/4-20. Retrofitting those took only a couple of minutes.