I don't have a specific point...
... but I figured I'd ramble on a few things anyways just to keep it "fresh".
Firstly, a thought occurred to me as I was running some free .32acp through my S&W 432PD. Yes, I know it's chambered in .32Mag, but i figured out a long time ago that it will also hold and fire .32acp since it's so close to the same diameter and has a very slight rim.
Why are there no .32acp revolvers on the market? You've got the very small NAA Minis, chambered in up to .22WMR, but the next leap brings you to the J-frames. Even in "accepted revolver cartridges" you pretty much jump from .22WMR to .32Mag. .32acp is a perfectly acceptable light defense cartridge, otherwise millions of Seecamps, NAA Guardians, PPKs, keltec P32s and the like wouldn't be out there.
So who's up for making a little birds-head .32acp 5, 6, or 7 shot revolver with the proper cylinder length so it's just tiny?
What else can shrink a revolver, hrmm.... briefly a long time ago I thought of something that would reduce the size of the cylinder. What's that? Not making a cylinder, but having discrete chambers on links, like a tank tread. Not very feasible.
In other failed ideas, it occured to me that if you tilted a cartridge at an angle to the bore axis, you could create a shorter magazine than the OAL of the cartridge, at the expense of width. But then it occurred to me that the staggered cartridges had no real way of orienting themselves forward, or if they reorient in the mags that it would have to be at least OAL otherwise they wouldn't fit. So much for the easy to hold .30 carbine semiautos...
Something to research: How much pressure management capability does a steel cartridge add over a brass one?