“The high voltage output lead from transformer to earth, I presume you meant earth leak test? “
no the high voltage winding one end is bonded to the earth. so you will get a reading from high voltage lead to earth. and if yes thats good
“With having understood, all this to be completely disconnected prior to testing so that I don’t fry myself and the oven”
dont forget to earth the diode capacitor junction every time you have had it on.
Dave