Some aspects of this thread are interesting, some aspects of it are inane if one remembers that businesses exist to make [that vulgar, albeit very good] profit!
Actually I believe in capitalism and free enterprise, very much so!
If NEF (a.k.a. Handi Rifle Inc.) was run by Handi loonies and not businessmen, I could see tweeking the product line to service fans for every rimmed cartridge out there.
But if one was planning Handi sales based on ammo sales in North America, methinks most times the choices offered by NEF/H&R would not differ that much from what we already are used to.
If was running a company like NEF, I'd look into creating a custom house to satisfy the barrel accessory program, but would also seek their input on what rounds customers popularly sought.
I'd also try to create a schedule that could be [roughly] followed (and shared with distributors) when producing limited or semi-regular runs of ..... say ..... .357 Maximums, .35 Remingtons, Whelens, .30-40K's or .303's or .762X54's every other year or every three years, so on and so forth.
But even Remington for example, before acquiring H&R and Marlin, would make a run M700 .25/06's (for example) to last 2 or 3 years worth of projected demands, not just one season's worth. This philosophy supported the program Remington had when they made their annual Classic M700 is whatever one-time chambering each different year.
As for offering the 7.62X54R, .303Brit or .30-40Krag, since the .30 cal .30-30, .308Win and .30/06 are already offered it makes sense to choose the .30-40K over the .303B and Russian round., altho a limited run could be done on them for collectors, etc. - after regular production was accomplished.