The same is done for the big guys too, reusing both the indoor and outdoor and just tweaking the algos on the board, occasionally changing a part.
If you look closely at each brand, you'll see some optimize more for the 12k, others more for the 9k version. If you are lucky enough in your use patterns, you can get 9k performance out of the 12k most of the time, and then get that extra boost when needed. Hard to get a super accurate picture on a continuously variable product installed in a very variable USA climate.
The risk of the chinese making everything is they now steel it too
They don't seem to claim any 'hyper heating' capability; maybe there is a parts quality or some other tech involved to maintain that which drives up pricing. Not an issue for SC, but mine was still running in consistent -20 temps for about a day, almost half the time in defrost mode.