On the chance this may be of some interest...
I'd decided I wouldn't mind having a little larger screen than what's on the RP, so I was experimenting with using my Note 20 cellphone. I'd used DSLR Controller in the past, but it isn't so up to date now, and so I decided to try a newer Android app called "Camera Pro Control". The wifi connection took a couple of minutes to understand, but using a usb-c cable was simple and gives a little faster response, and as of now I think it's very much worth it. A very nice phone app! Then I recalled that a couple of years ago I'd invested in a decent but not too expensive field monitor that is still practically new, so I tried it with the RP using the hdmi port. It also works nicely--but it doesn't have a touch screen and because it shuts of the RP's on-camera screen it necessitated using the buttons to move around the menu. It still worked well thought...and then I wondered whether I might use the field monitor over hdmi -and- use the cellphone via usb-c and end up with some extra capabilities!
Voila! It turns out that even though my larger field monitor turns off the on-camera screen, using the cellphone app gives me back the touchscreen capability to focus and change other options as needed, and any changes also show up on the larger field monitor instantly. Plus, the above app has a nice zoom capability that definitely makes it easy to ensure sharp focus which can also be checked on the larger monitor (which helps if your eyesight isn't so perfect any longer).
One last benefit of this setup is that using the cellphone over the usb-c cable (or wirelessly) means there's no need to even touch the camera unless you need to move it for some reason. No shaking it by touching the screen or touching the buttons on the field monitor, which leaves you free to watch the large screen if you like or move around and check the phone without ever jostling the camera itself.
Obviously this isn't relevant if you already use a large touchscreen tablet or if pushing buttons or touching a monitor or the camera isn't an issue. But it was a surprise to find that I could make use of both with the RP, which is liberating in a number of ways.
