Even in 28mm "modern" is quite well supported these days IMO.
I absolutely agree that my WW II books has still a lot to cover, but who am I to argue with my customers...
As said before I will sooner or later run a Poll to see what should be done next.
The Soviet TM book is well under way and Gear Krieg is also set.
For Pacific war I have drafted US Marines and Japanese army plus late War Chinese.
Everything else depends on
YOU.