Platinum silicone inhibition with Formlams Grey resin printed mold

We print molds for our project on your Formlabs Form2 with Grey resin.

Normally everything works great but this time something went wrong and we have significant cure inhibition problems especially in the air vent passages (marked red on the picture).

We exposure the print to UV using Form Cure for 30 min @ 60-70C or 140-160F.

Silicone manufacturer – SmoothOn general message is that the printed mold should be exposed much longer to UV then the general SLA printed part which to be used for display or any kind of fit test. They recommend 4-5 hours exposure @ room temperature.
What settings would you suggest to set up on UV Form Cure in order to get sufficient UV exposure from one side and not to damage/overexposure the mold from another side?