Nylon bolts work good, but they're like anything in our hobby, you have to develop a feel for them. Most of my 40 and 60 size airplanes have either 1/4-24s or 10-32s. If only two bolts hold the gear, then the big ones are used. If 3 or more bolts, then the "little ones".

I've never had one strip or break when tightening. That might be where the "feel" comes in. There is no value to tightening past about an eighth or quarter turn after they're snug. And if they strip or pop then, you got bad bolts.

The trick to using them is to drill and tap the plywood that was holding the blindnuts for the metal bolts. If the plywood isn't thick enough, glue in some basswood to get thickness.

The beauty of nylon is that they don't need lock washers and don't walk out if they get the least bit loose. They don't actually have any tendency to get loose like some metal ones do.

I use them for wing hold downs too. Beauty there is they aren't so easy to lose and they're so much easier to tighten and they're more than strong enough. They almost always fit the holes in the wings with a slight friction fit and that's good enough to keep them there in storage. And if they were to fall out, they'd be easy to find, even in tall grass.