After my last message, I've managed to set aside a couple of hours tonight to begin the job of replacing the "faulty" Parameter encoder.
I've followed the instructions given to dismantle the REV2 and everything went smoothly to get the board out and onto my workbench.
I then proceeded to desolder the "faulty" encoder. Not as easy as one could imagine since it's a 2 (+?) layer board. But after a careful job not to damage anything, the encoder was out.
I then took the replacements out of the package sent by DSI support, only to find out that they were PHYSICALLY DIFFERENT. In other words, the replacement don't fit. The base of the shaft is threaded, whereas the original is not which prevents the base to pass thru the holes on the front panel. Moreover, the shaft itself is too long !
So I then decided to resolder the old one in place. And reinstall all the screws, wire connectors, and numerous knobs in place.
The Parameter encoder still works exactly as before, randomly skipping values (mainly when going down, or turning it to the left). No better, and most importantly no worse than before. Luckily, I took all possible precaution and care to do the best job possible.
So, my advice to anyone who would be tempted to take on the job of individually replacing encoders, go for the whole board swap instead. Much easier, and at least the replacement board should fit. And that advice is coming from an electronics hobbyist of more than 30 years experience, with the right equipment.
Here is a picture of the two encoders, side by side. The one on the left is the original, the other is the wrong replacement part sent to me by DSI support. The second pic is the old encoder after reinstalling it. <moderator edit: personal attacks will not be tolerated. You have been warned>
As a side benefit to doing all of that though, I could finally get rid of a small white speck of dust that was caught between the OLED display and protective screen that was annoying me from the moment I took my REV2 out of the box. (poor quality control at DSI)

