If you really, really, really need such a spying app, isolate it with shelter. But keep in mind. As mird apps you install in shelter as more data will sebd the the spying companies. They will get ALL data from your work profile
The phone will also work from work profile. That’s no problem, but you are right with your contacts. As soon as you have transferred them to work profile whatsapp is using them.
And I’m sorry, I don’t understand a need of these caller apps. On my phone, the caller is shown if he transmitted his phone number and he is in my address book. If the phone number not transmitted I don’t know who is calling and I can decide to pick up the call oder leave it. Same I can do when the phone number is transmitted but not in my address book. With this solution I’m living since 40 years without problems
A better solution is to send all calls directly and silently to voicemail unless the caller is in your contacts list. If the caller is genuine they will leave a message. There were several FLOSS apps which could do this when I looked at it a few years ago. The solution I use now is never to give out the mobile number to anyone not in my contacts list. Businesses and officialdom get my landline number which always goes directly to voicemail. Genuine callers do leave messages. Friends & family get my mobile number. Immediate family also get a free virtual SIP number to call at landline rates. This is because landline -> landline calls are generally less expensive than landline -> mobile calls in UK. Yes, elderly parents still call landline -> landline most of the time. Perhaps some of this is useful in Italy too?
At the moment applies to landlines. For mobile phones the law is not yet active but will become so (based on a unique prefix). I hope soon.
Numbers that are not in my contacts: I don’t answer and then I look in the blacklist on the net, eventually I call back.
Hidden numbers: I don’t answer and forward to voicemail
I tried @dotcoma method of installing Should I answer in work profile under Shelter, but unfortunately it doesnt work, as I cant choose the app as the preferred app for calls (condition that is asked for the app to block the calls).
I cant take the risk of not taking phone calls that arent on my adress book due to my work (clients calls).
I’m using Yet Another Call Blocker from f-droid to prevent telemarketers. Works better when more people are using it and will report telemarketers. Not perfect solution for sure, but has been helpful for me.