Hera is the 1 point to 2 point conversion chart developed by Dick Vermeil when he was the offensive coordinator at UCLA in the 1970’s. Apparently this is still in use:
This was long before college overtime start in 1996.
Unless your team has demonstrated tremendous success on the 2 point conversion during the season OR you have just lost your starting QB (Even then it might be a bad idea: OSU-Mich 2013) I would want to give BOTH my offense and defense a chance to prove themselves in overtime.