Mig, It's called making modifications. T-nuts are O.K.,sort of. The more secure T-nuts have 4??? small holes in them, which enables you to screw them, (not hammer),into whatever material you are using. Nut & bolt is the way to go!
If you countersink the hole on the inside of the mount, you can then put a larger bolt in that is flush and then make sure you have two nuts on the outside. One to lock off the bolt and the other for the spring to attach behind. This is bound to last a lot longer than a screw into MDF. Or as Ken has said make a new mount out of marine ply. You have all the templates, just might mean you will have to disassemble your mount and cut all the parts.
When I was in the BAS, we made heaps of Dobsonians out of marine ply, and they are still going apparently. That was in 1988.
If you contersink the bolt head into the chipboard then it is effectively thinner and weaker. If you are thinking of going this way a new panel would be better.
Maybe a stinky, nasty experience with the really runny epoxy will teach him about the error of his ways. Afterall, telescope abuse is a serious offence
