INT+ (Intercom Signal) can drive 50ohm speaker. It has a 3Vpeak voltage level with a 500mW power. Regarding the backup power supply, I have nothing to do with it. I only design the headset electronics; power comes from the customer intercom system. Think about a headset connected to intercom systems that take inputs: power and intercom (INT+).

The pot is used for setting the output voltage. The converter should automatically adjust what you have set with the pot.

I want to limit the output power to 10W. LT3002 and the transformer can provide 12W at 12V output. I think that if I can use LDO with a maximum output current of 800mA at 12V, like in the circuit above, I can limit the output power while having a stable 12V. But I must increase the output voltage (out_flyback) to get 12V from LDO. By increasing Rfb, I can get 14V, but the transformer (ZE9672-BED) is rated for 12V. My question is increasing this voltage to 14V in the circuit (still 10W) might be a problem for the transformer?

I added all of the related information.