Excellent work you have done on this thread I am surprised you have not got any feed back with this. The subject may have been covered in great detail previously but I have not come across it.
I do have a project in the pipe line that in my opinion would greatly benefit from the addition of an epoxy coat and also improving strength in the joints. This project is a little in the future but I hope you will be around for me to pick your brains on the subject when the time comes.
In your opinion what thickness of coat on say MDF or plywood would be required to make a noticeable difference with stiffness? For instance if I brushed on a coat would it increase the stiffness by 5% 10% or more? Just a rough answer will do to give me an idea so I can gauge the benefit of using epoxy.
One last thing do you think that over time the epoxy coat may crack due to the flexing of a router frame?
Thank you for your time and trouble,