I think your best bet is going to be start small and work from there.
If you give us the details of the parts you are going to use, then maybe someone can sim it for you.
Stop worrying about maximizing your MOT and make something!
Yes that is the circuit I am building but that is not where I found it.
MOTs have 100 turns on the primary instead of 200 turns like it should. 100 turns makes the transformer run at full load with no load applied. I can put any size wire I want on a transformer secondary as long as it fits in the core opening.
MOTs duty cycle is very low they can not run full power more than 10 to 12 minutes they get hot enough to smoke. The thermo over load will shut the power off before it burns up the transformer. So with that in mind I can under size the secondary wire if I need to.
MOT secondary winding is 1.2 volts per turn.
13 turns will give me 15.6 volts. If I take the core apart I can get 5 secondary windings with #12 enamel coated copper wire in parallel that is 100 amps. I can not buy #8 enamel coated copper wire so it will need to be THHN there is only room for 2 secondary windings in parallel that = 40 amps. I might be able to get 13 turns of #4 wire = 70 amps. 70 amps will work for 10 minutes. I have a 5 KW laminate core I have been saving all I need to do is wind a primary and secondary coil.
40 years ago I worked for a company that made transformers so I don't have any trouble winding my own I know how it is done. Learned it in college engineer class too. Never worked with Mosfets before.
This use to be a MOT. Now it is 200 turn, 120 vac primary, 48vac with center tap secondary, power supply transformer for a 380 watt transistor amplifier. I also build a Dynaco 120 tube amp, made 2 audio transformers and 1 power supply transformer. Transformers are easy.