Japanese mahjong can be played with numerous variations of rules and scoring combinations. There's nothing to stop you including it in your own house rules when playing with family or friends. Just don't expect to see it at clubs, parlours, tournaments, etc!
As noted, perhaps a yakuman (top limit) would be a little generous. Maybe award it a baiman or sanbaiman limit instead?
Then again, the official rules themselves aren't perfect. San Kantsu (three kongs) is so rare it should be a yakuman and Sū Kantsu (four kongs) should be a double yakuman at the very least!
I also think your serpentine hand is quite "messy" compared to the standard Japanese limit hands. It's not an especially interesting or attractive form.
