It's in the title really. Is there a way I can stop Zoom highlighting each screen with a border and showing the screen numbers while I choose what to share? I've attached an image to show what I mean
The option you are looking for isn't available and no settings to modify that option. The number shows up if you have a dual monitor and it was highlighted meaning that the screen is selected. It is hard-coded.
I think that's a good update. Please feel free to submit a feature request, or suggestion from the page https://zoom.us/feed