Health,
“Instead of getting blinded by this Poisek or that one -think how similar is the type of cooking to the Meleches Hamishkon.”
That doesn’t address havara.
“Even if it wouldn’t be, the bishul of the cholent would still be D’oraiso.”
Why do you say this -because Rav Moshe says so about a microwave?
What does one thing have to do with another?
The fact that R’ Moshe holds a microwave is D’oraiso, despite the fact that they didn’t have them in the mishkan, shows that you have fundamentally misapplied the concept of “dumya d’mishkan”.