keys are always remappable. the only thing that tends to be a bit weird is supporting chording, mousekeys, and other weird stuff properly -- imo this is the value of basing the phantom on the keyboard. i could care less about different layouts, as it requires doing things like special ordering keys.
anyway, i think more generic symbols are better choices for the R1 modifiers anyway, but when it comes down to it, i just don't care that much as long as i have nice keys to type on, so w/e