PiDisplay VS pinn

So far the best instructions I've found are here:

I have tried to follow the instructions on the official Waveshare website, found lots of github instructions, heck I even found some on amazon questions. None of this worked, the screen is blank and not showing anything.

For dual booting look to PINN - I prefer one OS per card as there is less chance of a card error hitting lots of operating systems / running out of space / deleting the wrong partition.

You should be able to achieve that by using PINN. It's an operating system and boot manager for Raspberry Pis (plus more features that you probably don't need).

You could look at PINN https://github.com/procount/pinn as the author is active on the Pi forum.

PINN is a can be found at https://github.com/procount/pinn

After more reading: The "Raspberry Pi Imager" seem to have something similar called "PINN". Is PINN similar to BerryBoot? https://github.com/procount/pinn/blob/master/README_PINN.md

I would not use NOOBS at all now - its way old and PINN is a better option if you do not use multiple SD cards.

You could have a look at https://github.com/gitbls/sdm for image management or PINN as a NOOBS replacement.

NOOBS is deprecated and no longer maintained or recommended by Raspberry Pi. If you still want a NOOBS like installer then use PINN which is an enhanced fork of NOOBS that is still under active development.