BrianHolmes I dont think that's accurate or at least not what the OP is asking.
[deleted] Do sms apps like "Simple SMS" work in secondary profiles if I am using it as my "owner profile"?
Yes, SMS apps work in the secondary profile.
When I was testing a setup similar to the OP in which my owner profile was naked and a secondary profile as main, I was able to install and use Google Messages in the secondary profile. Actually, I had stock SMS app disabled in my secondary profile. I did have some issue with duplicated messages but I dont think it was related to profile setup.