That would be an awesome feature for this kind of situation, but unfortunately there isn't a way to do that natively on GrapheneOS.
Personally, if I were in your situation, I'd create a new user profile for work. The requested app could be installed in this profile and be used while on the clock, then once clocked out, end the profile's session. This way is less elegant than the way you mentioned, but it would be effective as long as you remember to end the profile's session every time.
Here's some information about how GrapheneOS improves Android's user profiles features: https://grapheneos.org/features#improved-user-profiles