I was on .0400 since I got the Mavic last year. I briefly upgraded to .0600 (I think it was) and began to get NFZ errors, so downgraded back to .0400 to stay safe.
Recently got the
goggles and a lot of the functionality was missing, so I bit the bullet and upgraded to .1000.
Long story short, no problems whatsoever.
I live right beside a small unused airport, and get the notice, but have never been restricted, here or anywhere.
Granted, I've not tried to authorize in larger controlled airspace yet, but I had problems with that even on .0400.
So I think some of the apprehension of the later versions might be unwarranted. At least for now it seems all good. I'll keep you posted.
BTW, contrary to what to might have heard, nothing is "forced". I have had notices to upgrade further and simply ignore them until if and when I choose.