I will give you an example:

If I was able to build my own engines and rockets. I would reevaluate the entire concept of design from the ground up. Why are they 18mm, 24mm, 29mm engines. Not to sound Spinal Tap 'ish" but why not 20mm motors? 25mm, 30mm.
If you can build the whole system, engines to rockets...build something entirely different.
Sure you can continue to make and market standard sizes...but maybe there's innovation in a system that is not like all the other sizes out there.

I've read some of the posts in the other threads and it's "bring back this or that" ...bring back the century style parts kits. I look at the stable of Semroc kits, and most seem to be designs that have already been made and now are brought back or upscaled sort of COTS plans. Now I am a HUGE fan of Semroc, and love the company. I think they are the best thing out there, bar none...but now is a chance to redefine model rocketry. Why not take the big plunge...now motors, new mounts, new kits. Make it something exclusive to Semroc. A single source provider.