United Airlines -- use of premium cabin restrooms

Three of my last four flights to Europe (all since last October) were in United PE.
I used the Polaris restroom every time. I normally sit near the front of the cabin where I am close to that restroom, so it only made sense for me to use that restroom instead of giong however far back into the economy cabin.
The FAs closed the mesh curtains between cabins once we got in the air, but it usually got re-opened, and not reclosed, at some point.
They made a general announcement "please use the restroom in your own cabin" but most if not all of PE on each of those flights used the Polaris restrooms and nobody said a word.
I didn't do any research into which cabin bathroom I could use ahead of time, so maybe PE is allowed to use the nice bathroom and that's why no one said anything.

On United, I sit in the back of the plane with the peons but I usually try to still get in my minimum 250 steps each hour on my fitbit, so I establish early in the flight that I'm one of those people who spends a lot of time in the aisle wandering up and back, and usually during one of those laps I can use the WC with the nice lighting and sink, and then I'll go and smile and nod at those other characters on the flight who like to peer out the porthole of the door, you know the ones, we all guess that they still do planes and ships as a modelling hobby, no?

Thank you, folks. I want to add that I am not trying to abuse anything. I just want to triple verify United's new rule. I certainly won't use the business class restrooms, should I choose another airline.

As others have mentioned, United asks that you use the restrooms in your section. Premium Plus is still considered economy. And I just googled and can’t find anything to confirm that United is advertising what you mentioned. And it is not mentioned on the United site that describes the Premium Plus experience. You can always ask the flight attendant.

I fly on United, in their "Polaris" business class somewhat often (will be flying to Europe that way in September). United isn't my favorite airline either, but I think it's actually pretty good for a US airline (and their Polaris business class is perfectly nice, nothing to scoff at).

IME, I think most of the time, United cabin crews are generally going to want you to use the lav in your cabin. There will be times when they don't really care one way or another (eg late at night when most passengers are sleeping or trying to). There will also be times when they would actually prefer those seated in the forward sections of Economy or PE to just head up to use the lav in Business Class - while they are serving, and passengers trying to get past them are just in their way.

In your case I suspect it's going to be a YMMV situation - probably no guarantees, nothing in writing, you'll need to "read the room", and just give it a try when it seems OK, being prepared to make a 180 if you get much pushback. Just be polite and fairly discreet, they're not going to open a door and throw you out (no trans-Pacific flights operated by 737 MAX 9s...).

Enjoy your trip.