Keychron mechanical keyboards unofficial support

I don’t know that “relative merits” exist. They’re basically all personal preference.

Low profile keys are shorter than normal; some people like that

ANSI keyboards have a wide straight enter key with backslash above it. ISO has an L-shaped enter key with the backlash taking up half the backspace key. JIS keyboards are a Japanese-style layout. Again, personal preference.

Percents: various key reductions, chopping off some of the middle cluster (96%), numpad (80%), both (75% and 70%), function keys (65%), arrow keys (60%), and number keys (40%). Which you might want is… personal preference.

Models are just different model numbers with different layout variations or material variations such as metal vs plastic frame.

Keycap types are different kinds of plastic (ABS and PBT). Double shot means the labels are molded in separate plastic from the rest of the keycap. More expensive but more durable, barring easier mfg defects. Dye sub means the labels are printed on the keycaps through the dye sublimation printing process. They can wear off after many years of heavy use. Shine through means LED backlighting shines through.

Keycap profiles are the most complicated but they have an article that specifically covers it and once again it all comes down to preference really.

Other than that… did you have some specific terminology you wanted to ask about?