Thanks to you and Sumit for the reply.
I am very angry with microshift, I do not have the time to go behind its ****, now win10 is working and I do not want to change to 11 because there is the high risk somw sw will not afterwards. To force the installation of 21h1, I am not sure it will work since now it has 11 ready and no 21... and again I do not want to risk to waste time after something is wrong. Maybe I will wait like you say the 24 Jan to delay the ****, but only another 4 weeks; or maybe I let it go and then I recover completely to original configuration, but this is another 2 days of work. Someone should sue microshift for not asking permission to do this kind of **** to customers.
A few months ago I was forced to remove the innocuous pgp10 which I used only as single file encryption, ridiculously it said it is incompatible with 20H1. Very angry