Can't really help much there... I haven't bought a keyboard in years. But once you drop that first qualifier the availability of options just goes bananas!
jdnewmil
I suggest that you should spend less effort looking for special hardware and more effort learning how keyboard mappings work in your OS (e.g. [1][2]). "Linux" is a very powerful chameleon because hardware vendors almost never cater directly to that market.
[1] https://linuxconfig.org/reprogram-keyboard-keys-with-xmodmap [2] https://github.com/xremap/xremap
LA batteries don't "only trickle charge", but a) the cost per kW of UPS equipment is usually significantly higher than the generator, and b) the generator has a much higher surge current capability than inverter-based sources, and c) the power that actually goes through the battery loses anywhere from 10-30% in the round trip, so you get less usable output by routing power that way. If the cost issue becomes a smaller obstacle and you can be clever about bypassing the battery when appropriate, then like hybrid cars you can overcome those challenges... but not everyone or all affordable equipment can do that.
This is th trouble with rule-by-self-interest... eventually different people's self interests clash. Now what was the solution in the constitution? oh, yeah, rule by laws... but that clearly didn't work... /s