Im with u sir in everything u r mentioning
i have a sony x900e it is a 55 inch TV and Im happy with it for 3 years now
I want to upgrade to 65 inch and yes I know OLED is superior technology to FALD LCDs in every way despite brightness
in 2021 there will be OLEDs TVs with 1000 nits brightness but every time I want them I reconsider cause of burn in issues
I hope mini led meets expectations for time to me to upgrade
I know this might not be an easily answerable question but do most of the games you play have colourful and bright art styles (Like say Mario) or more realistic/darker visuals like Batman/Metro?
If you don't really play things with tons of big bright scenes the OLED is the right choice. The idea that they "aren't as bright for HDR" is kinda misleading, small/thin highlights on the screen like neon edge-lighting on a sign or just super bright highlights of any size next to really deep shadows/black are generally going to be brighter and look much better on an OLED, conversely on an LCD they will normally dim objects that are much smaller than a single dimming zone or super bright objects next to dark areas regardless of size , which will be most HDR highlights on most LCDs, since even the best ones might have pretty big zones, in the 65" model especially.
I can't help you with burn-in worries except to point you to the videoes I'm sure others have already, like rtings long-term OLED tests, but don't be discouraged from buying OLED due to it not being "bright enough for HDR" unless you only play games with insanely bright presentations like with hardly any darker areas on screen. In those very very specific cases a good FALD LCD will look "better" in some ways, but its not worth the tradeoff for 90% of people imo.
I have a 65" TV where the zones are only around 2 by 3 inches each and I still get blooming in challenging scenes (bright spaceship engine over dim/near black starfield background) even though the object is actually quite a bit bigger than a single zone size on the set. So what I'm saying is miniLED will still have these problems even with thousands of zones unless they use image processing to dim things down significantly and away from the creators intent, apply reverse vignettes or other things you don't want if you value accuracy.
I'd just buy one of these "new" custom panel 1000-nit 2021 OLEDs that Panasonic had exclusive access to for two years (I assume, no way to know really), because miniLED will not be a revolution, at best I would hope that mid-to-high-end sets will match the dimming capabilities of best ever released from the three big brands:
(All zone counts are for the 65", because even though the Sony and Samsung are available in 75", the Pana is only 58" and 65", same zone count for both models according to displayspecifications.com)
Sony ZD9 - 646 zones
Panasonic DX902 - 512 zones
Samsung Q90R - 480 zones
I do think the dimming algorithms are getting better all the time though, so they possibly will manage to look a ton better even with miniLED backlights that would otherwise produce comparable (in whatever way that may be, I presume its different in how it works since the LEDs are physically smaller) results to the models I listed.
The best money for most people will be spent on a 2021 OLED that hopefully allows closer to 600 nits full field, which is what you get from super high end LCDs, reducing the problem I spoke of at the start of my post to a point where its negligible.