I'd support this with the inclusion of a few added parts.
All Submission finishers must be okayed by Staff - that's non-negotiable. You no longer "need" one, so they have to fit your character.
Anyone uses it before the 3rd it: doesn't count towards the 3 finishers AND is subject to review at the end of the match. It's up to the person using it to make sure there are no accidents. If there is an accident (Via Sig time out/stupidity), you must immediately break the hold(?), suffer the momentum damage. If you continuously have "accidents", then you have your sub finisher revoked.
Also, no crawling to the ropes to attempt a break, otherwise it defeats the purpose.
If you want to go for the dramatic CRAWL spot, you must use a move that isn't a finisher. This is because when you're trapped in the sub finisher, it causes a considerable amount of further damage on a standard hold, therefore using it as say, your first finisher, means that you're putting on constant modified damage to your opponent - which isn't fair.