How 'bout 29mm? Then you can slap in 29/40-120 reloads, Econojets, E9s, D12s, etc. Unless you're itching to cluster or something.
I've an upscale Tangent (very similar to your vaporators . . er . . Astra) with a 29mm mount which I've flown on all sorts of motors already and it's only a few months old. It's intended to take some of the load off of the Maxi-Alpha which is on it's third overhaul and 70-something-eth flight.
A simple adapter is used for 24mm motors, and the adapter has the thrust ring so it just slips in the way it is. The 29mm retainer also holds in the 24mm motor. A spacer is used for C11 and D12s. E9s and F21s fit directly. 24mm reloads work well too.
The retainer is a drilled out and cut down PVC 1/2" PVC to 1/2" copper adapter. I wanted an Aeropack but couldn't justify $25 on a rocket that I have less than $10 in parts. I already had a BMS nose cone left over from another project and with a little bit of sanding to shape it looks pretty good. Basswood fins for strength. I've been recovering it with a bright yellow 12-inch nylon 'chute custom made by my wife, but I'm planning to switch to a streamer when she gets a minute to sew together some scraps.
Imagine an F20 or that new Redline SU . . . .
