Hallo platypus,
that is basically a good idea, but the tests would be quite extensive and exceed my possible time expenditure for a purchase software.
I would actually expect DXO to make clear and reliable statements about this.
I don’t want to test, for example, with 60% of the possibilities, then work with a clear conscience for a few weeks and then catch a function that produces errors, and I get annoyed.
There are a few other things that I find progressively not good.
This morning, for example, I installed V5 on my main computer under Windows in addition to an already installed V4. Of course only after I created a current backup of the V4 
What would be so difficult that the installation routine of the V5 recognises an existing V4 and then gives me the option via query to possibly remember the V4, or also immediately gives the option to select for DB and cache directories. I know that the versions are separated in the user profile, but then you first have to start the V5, change the settings in the preferences (which is not possible with MAC) in order to be able to work.
Certainly complaining on a high level, but why not 
For me the time of image processing starts now, so there is no time for testing.
Edit: And together with DXO we should work to prevent from this events Lost all ratings in PhotoLab Elite 5.1.0 ??? - #3 by RKyburz