I guess safe option is to start again in my local airports - EGSX, EGSS or EGTC then see if it smooths out again before changing anything.
Not so sure about Papua New Guinea 
I don’t get money for this (self)promotion 
A nice try for a better Quest 3 life:
I did try that but could see the black frame at around 90-92% but i’ll try it again.
Is there a recommended setting for the resolution override setting (on a 3080ti) when at 85% FOV ?
I see the a very smal frame on the bottom in @ 89%, but only when I lift my head. It’s a very small area. I don’t notice it during flights, unless I look @ it 
I use VD and Godlike mode on my 7800x3D OC and 7800XT OC. I can’t help for a settings recommendation on an 3080ti. Sorry.
With the AMVR replacement “interface”?
Not really. It depends on too many factors. You just need to twiddle things until you are happy. I think it’s the only way.
I am still fiddling after 4 months, even yesterday I think I found a better combination so will see if that holds up over the coming weekend!
FWIW on my 4080: VD Ultra / 72Hz + SSW / DLSS Quality / OXRTK 3400 ish / CAS upscaling with 50% sharpening / 85% FOV / Quality + Wide preset on Foveated Mask.
I tried the thing I mentioned: DLSS Performance (so it’s 50% resolution from the Sim) then 4128 resolution (I think that means it’s going 2:1 upscale to the 2064 x 2208 pixels per eye res of the Q3 but the 2nd figure does not match up on the same 200% ratio according to the spec so 
) and whilst the clarity was fine, it was not as smooth as making higher in-game resolution with the better DLSS then a lower resolution in TK. There is defo a balance to be had
Yes, I have the interface on the middle click-stop for distance, maybe I need to try the upper & lower stops as well.
I’m off for a play shortly, i’ll try 85% again…
Hmm, maybe I have a different version! I am not sure I have this feature… I just have a “tilt” (3 settings) for relieving pressure on cheeks. I will have to look again! If I can get it a bit closer to my face (less ‘binoculars’ border) and then have to increase FOV (less sharpness) I’d probably take that!
I am using these exact settings with a 3090. Like you, have tried all combinations, but this seems to be the best balance for visual clarity and performance. Well today anyway, tomorrow , it may just not work !
YEAHH exactly this. So annoying! 
On a 3090 so similar to your 3080ti, I have this set between 3400-3500 . Can go slightly higher with FPS friendly aircraft and scenery.
I’m just about to throw in the towel…
I tried 85% FOV and upped the res a little to 3400, the picture was amazing and very sharp but yes there were black borders; I was willing to accept them in exchange for the clarity.
It was going well for about 10 minutes, I did some deliberate dodgy moves over Duxford to see if it was double-imaging again - nothing visible, landed had a sip of coffee, took off again and back comes the double-image, all over, absolutely migraine inducing.
I cut the res value to 3200, nothing, no change. Turned off Riva, turned off ASW to see my raw FPS, my thinking was to give it some overhead.
Turned down OLOD & TLOD to 100, backed off a few other settings, in the end my raw FPS was 45+ which was pretty surprising I thought.
Turned ASW back on and restarted VDT just to be sure, made a flight - looked good, for about 2 minutes then… double image. I have found I can also do it just by moving my head in towards the instruments for a closer look - the image doubles then clears as you stop head movement.
Hovering, looking at a windsock across the runway - pretty close - the double image is about the same as the width of the drooping part of the windsock - it’s two clear images that are out of sync sideways.
I really don’t know what else to try now, seems its not overhead as there is plenty of that. I now know the image clarity can be found which is what i’ve been after all along but the doubling is really bad so can’t use it without eye-strain and/or a bad headache after 10-15 minutes.
You mean it started doing it during flight? Not taking the head unit off (or lifting it a bit so it thinks it’s off and it goes into the black // sleep mode)?
Yeah it seems to start whenever it likes, really grinding my acorns now 
You think its fixed, relax and bam, back it comes.
What encoding are you using H264 , HVEC … and what bitrate have you got set or is it set to adjust automatically . I have had this effect in the past using SSW but not since the more recent updates.
Its on AV1 10bit and 60mbit rate, I think it was set to adjust automatically.
Just for the sake of trying, maybe try 10bit and manually set a rate of about 120 .
Which 10bit?
And 120 in VDT streaming settings?
HEVC 10 bit in PC streamer app and yes 120 in the VD streaming settings in headset
OK, i have just enough time to boot up and try this before I go out…
Best to leave auto bit rate on ?
At 120 i leave off , but 60 seems very low even in automatic . Ive just looked at my own system and auto sets it to about 150