Hi, again @paolo.p !
I attached examples of config.txt and userconfig.txt of a working system with RPI4B and 7.9" DSI display.
config.txt (189 Bytes)
userconfig.txt (275 Bytes)
Files: WS_xinchDSI.sh and WS_xinchDSI_MAIN.sh can be found in driver package zip. Modified version attached.
5.10.92-32-mod.V1.zip (35.1 KB)
Everything is working with this display, so no worries! 
I guess displays with HDMI will be easier to set-up and probably more future-proof solution…
However, currently, especially if you want to install Peppymeter, it is few more command lines to get DSI drivers setup and this display going.
So you, Guys, decide how much more hustle it is. ;p