No prototype at all !
I design a lot of electronic consumer circuits that run direct off the mains with no transformers.
Most are fully designed and tested using Electronic Work Bench or similar emulators.
That make smoke testing work without the fire extinguisher and the lack lack of soldering is definitely ROHS compliant.
After few blown electronic software fuses and damaged meters the circuits work quite well.
I only needed spec sheets to make it work. Send the finished circuit to someone else to do the final smoke test.
Move on to the next design, with not so much as a burnt finger.
Plenty of circuits get created to be incorporated in other larger items like this and never see a PCB. It might be SMD, thruhole or just birdsnest.
That's often what happens.
Super X3. 3600rpm. Sheridan 6"x24" Lathe + more. Three ways to fix things: The right way, the other way, and maybe your way, which is possibly a faster wrong way.