mmmm
I think you simply need to do a test run to see how it works.
You don't have to uninstall them from the secondary profile if you don't want to.
It doesn't matter in which profile an app is located. Wherever that app gets updated, it will get updated in all other profiles as well.
It also doesn't matter if you update the apps inside Owner, nor profile 2, nor profile 3, etc.. in whichever the app gets updated, it'll then be updated universally.
In my case, I want to have all my apps being updated in Owner SIMPLY because I want to be able to push apps to new profiles quickly and easily. With my current setup (Owner is blank, Profile 2 is daily driver with most of the apps/Play Store) I cannot easily install apps into other profiles. To install them in other profiles I would have to, for instance, 1) download the APK to a USB drive and manually move them 2) install Google Play Services THEN log into my Play account THEN download those same apps. All that instead of being inside Owner profile, going to Settings -> System -> Multiple users, and installing the apps from there.