Sold a few of the US made ones.
Asked Springfield about a 14" barrel version for Canada; they understood the appeal, but it would have been a NFA firearm in the US. More complex to manufacture and export.
I suspect the trigger guard is there to keep the lawyers happy.
Without a trigger guard and with shorter barrels, they would fold in half - a neatly fit into a tool box, knapsack, etc. Handy little gun to have about.
These aren't intended to be general hunting firearms. I think increasing the caliber and gauge isn't the way to go. Stay with .22 (LR, WMR, Hornet) and .410.
From the standpoint of an emergency gun, .22WMR might be best. Ammunition can be had in fmj, light and heavier expanding choices. Even .22WRF for less destructive effect.
Don't expect that the barrels are going to be regulated for a single point of impact.