Ah clear, you gave it a well thought, so that's fine. UI Policy / Client Script, both are possible.

In this case, actually, are any fields hidden according to your script? My guess is, the if statement won't work at all!

So the first fields under "// hide all LoB apps" - apart of the typos - will work? But the ones in the if statement won't work. Is my guess right?
That's where you could use the UI Policy condition for.

You are trying to combine two actions now in one. While having no condition on the UI Policy, will make this only run on load, not on change of your value. Setting up an additional UI Policy would do the trick.

Kind regards,
Mark