Apps in other profiles and Private Space can be viewed in owner profile.

OpenBased

Apps in secondary profiles or private spaces can be viewed from the main profile by going to the following settings page:

Settings -> Notifications -> Notification read, reply and control -> Launcher -> See all apps

This gives a list of "apps shown on device" and shows apps in both secondary profiles and apps only installed in Private Space (shows the private space icon on the app).

Novalissoide

OpenBased you got there right before me, 😉
That is one of the few remaining checks that works under the setting 'Hide Private Space: ON.

They've been getting fewer

Novalissoide

OpenBased By tapping the Private Space entry in Security, one can also indicate if or not the Private Space is being utilised on the device, just by the question for Pin.

Novalissoide

OpenBased found one more;
Settings > Connected devices > Connection preferences > Printing

If you have a Private Space, deactivated, 'hide Private Space' is ON, then still a menu 'Personal' is there. It's just empty, no options, but it wont be there if device is without Private Space in use but closed. This may also be true about user profiles, haven't checked that yet.

secrec

OpenBased Apps in secondary profiles or private spaces can be viewed from the main profile by going to the following settings page:

Of course it is. Applications are only installed on the device in one place that is outside of all user profiles, and it is simply enabled or disabled for each individual profile. When enabled for a profile, it creates a userdata path for that application that is unique to the user profile.

Novalissoide

secrec yes, but at least for the Private Space feature there seems to have been some recent effort for the 'Hide Private Space'-option to be a bit more 'hidden'.
(Not the option, the effects of the option)