I am using shell.openTab to launch scripts many times that might only last a few seconds. They do not go away without user input. I want to be able to close those tabs when the script is done running, otherwise I end up with 100s of tabs. They simply stay on "Press any key to continue".

You can use multishell.setFocus to set the focus and then set the focus back to prevent that.

For example:

local currentTabId = multishell.getFocus()

local newTabId = shell.openTab('hello')
multishell.setFocus(newTabId)
multishell.setFocus(currentTabId)

But in advance, if you want to complete prevent the tab being showed on terminal, you should directly invoke os.run with coroutine or parallel

I am using shell.openTab to launch scripts many times

Hrmr, that feels like a bit of an anti-pattern. Do these need to be external scripts, or would it be cleaner to write them as functions, and then use a coroutine manager for parallelism? Would you be able to share your code, might help make this a little clearer.

Afraid I'm going to mark this as "wont fix" for now. As mentioned, my gut feeling is that spawning hundreds of tabs probably is the wrong way to be doing something. Happy to re-open if there's something I'm missing though!