This Pc I performed the change is my personal machine with a lot of other programs and data that is important to me, MSFS is there for my use when I am at a different location, and only with a simple Joystick, the main MSFS is in another machine with all the hardware attach to it for serious flying.
First I clone the C:Drive to replace it with a larger drive, (I use Macrium Software) after checking the cloning was OK, I resize the partitions to use the full new drive, I use Partition Wizard, which is free for several light partition duties, otherwise you have to buy a license.
I try MSFS, i did not work, went to the Xbox, remove it from there, not from Windows Uninstall.
Reinstall it, it took 2 hours. ( I have 1Gbs fiber connection).
When I start it it was exactly the way I had before, I had removed several planes I am not interested like the Howard Hughes monstrosity, (this thing barely lift off the ground IRL , why would anybody wants to fly it, plus 5.6 Gb space) Orbit Hospital, etc.
I deleted all the caches, all the old settings were there.
By reading the notes of the last update, I removed lots of mods I had in the Community folder, including all the acft mods, lights mods, all the garmin mods (They are added by MSFS now), only left Navigraph and Honeycomb. I do not use any scenery, either free or bought, MSFS provide plenty of it.
Then I tried the Beechcraft King Air 350i, which a lot a people seems to have problems with.
I started dark and parked, got engines on, everything else working fine , took off went flying for one hour trying the PFD, MFD, etc, use the Autopilot briefly, I had no problems and landed.
My GPU during the flight was 60%, CPU never more than 10%, temp 65C and 81C respectively, frames 70
My settings are not very high, I use DLSS, I am very happy with the performance. I have had problems with the Autopilot in several other planes, the Cessnas mainly, they have a tendency to drift and fall, but with a little bit of coaching they recover, I have also found that these problems originates when you are using HDG and NAV.
My personal take on the Community folder is that is the source of many problems with the sim, after a while you lose track of what is in there, and keeping track of all the changes and updates to those mod is a full time job, after all I want to enjoy flying when I want to, and enjoy life in full. If you do not use acft mods you can see how good or bad the MSFS is. Right now a lots of planes are getting very good without mods.
This PC is a MODEL LEGION 7i 15MH05 16Gb with nVidia GeForce RTX 2070 with Max Q 8Gb . I do have 2 drives of 1Tb each now.
The other PC with the Honeycomb Hardware and MFG pedals, with 3 screens is exactly the same.
If I had to do the same replacement again I think I would follow the advice of TheSevenFlyer , you don’t want to write anything into the new drive if you are going to clone your drive, see Editer suggestion