All USB keyboards distinguish between left and right Command, because it is part of the USB standard to do so. Some keyboards have a setting (via DIP-switch or other) to set the Alt and Command keys in Mac or PC configuration: that changes which USB-specific codes are sent.
The rest is up to software on the host.
What matters is what keyboard mapping the A500 Mini uses. I hope it is configurable.
The classic UAE program (for emulating an Amiga on a PC) have some mappings that aren't straightforward. \| is on Insert, Help is on End, not on the key on the bottom row where Checkmate has that text.
BTW, WASD Keyboards offers
custom printed keys, on their OEM-profile thin ABS.
I dunno about quality, and I have not ordered anything from them myself for many years now.