Output will be similar, but not identical.
While PL and PuR share technologies, some are implemented slightly differently: PuR is intended to be a preprocessor or plugin for other apps that handle colours and tonalities differently than PL which means that differences do exist and have to be handled by the user, no matter what comes out of PureRAW.
If the question is “I have PuR , do I need PL?”, the answer might be “if you’re happy with PuR, don’t bother with PL and equivalence of output images”. If one has PL, there is, imo, absolutely no need to buy a PuR license.
Necessary? No! Make your output look like you want it. Learn how to get there, the only obligation is to you and your artistic vision or intention.
What is “correct”? Make your output look like you want it. Learn how to get there, the only obligation is to you and your artistic vision or intention.
Long story short: Like anyone else’s, DxO apps are tools that can help to convey (or prevent) your artistic intention. How you “Make your output look like you want it” is a matter of trial and error and of learning what helps and what doesn’t.
Try, go wild, undo if you don’t like the looks, but maybe wait a day before you do.