Regarding security locks, it's up to the app to implement that if it is to be done properly. Many apps which store sensitive data do that.
afaik third party app locks don't work properly. I remember one GOS dev talking on matrix about how third party implementations of security locks are bypassable, and shouldn't be relied upon.
It's not possible to have two different versions of the same app in one user profile. Some apps like Twitter allow you to sign into my multiple accounts within the same app. The other option is to install the app twice. The second time in a different user profile or a work profile.