The WEAKEST points in all this is 2 things.
1. Regardless of the sixe of the CG breaker, the RECEPTACLE is rated at 15 amps ONLY
2. The adapter down to the 15 amp from the 30 to 15. The adapter and its 3 15 amp pins are also not heavy enough to do a FULL 15 amp constant draw.
To the OP, If you do this watch the adapter from 30 to 15 and you will see it will get melted and the pins will get discolored and will look corroded. NOT GOOD as you are drawing more current that it can supply. Remember, the system WILL allow you to draw MORE than 15 amps. There is no magic wand that stops the excess current draw when you exceed 15 amps. The supply breakers and wiring will allow higher amp usage and the adapters will take the hit. Doug