I personally would not mix the two but won't argue the personal experiences of others.
Techron is recommended only once per oil change. People have done Used oil analysis where the results after using techron are skewed when techron is added. A small percentage can get past the rings into the oil.
The PEA which is the effective detergent in Techron is said to be most effective when heat cycling. IE short trip driving as opposed to highway driving.
Some on another forum use a very small dose each tankful, much less than the recommended full dose. Don't know how effective this is.
I'd personally run the Techron or other PEA based fuel system cleaner through x amount of fuel and then add Stabil right before refilling the tank to minimize condensation for storage.