@OP: Naming and shaming in the main forums is forbidden by the site rules. Next time, please keep abusers anonymous.
Chess.com also has a Fair Play Policy designed to punish players who unsportingly make people wait as you have described. Your opponent should be punished according to that policy. The site has no need for your suggested time control modification.
Not more than 1/5 of total time may be used on one move. I'm playing against many sore losers: As soon as I make a decisive move, they get upset and just stop moving. I then have to wait 10 minutes for their clock to finally expire. If the 1/5 rule were implemented, I'd only have to wait 2 minutes for them to lose.
I'm typing this as I wait for [name deleted by chesserroo2 after hearing forum rules] to move, since he/she lost his/her queen on the third move. Why can't they just resign when they blunder like that. Oh no, a lower rated player caught their mistake.