Many thanks for replying (and on a Saturday! - please go and enjoy your weekend, and leave this for next week).
"Do you have zoom enabled in the vr settings?"
Whoops sorry - yes that was it. I did a complete wipe and reinstallation and had completely forgotten that this setting even existed. In my defence, the zoom option is not mentioned in the VR learning centre article - though I was still inept enough to miss it in the options.
"As for the re-calibrate issue..."
I'm not sure about this, but it seemed odd since I don't recall this behaviour in 4.3. I noticed because I somehow managed to get my view position misaligned so that for me to look straight ahead in VR, I had to keep looking up (in reality); once in this situation, the recentre did not help as it only recentred in yaw.
I have nvidia 399.07. Sorry I should've tried updating already. I will do so and let you know if anything changes.
For Oculus home, I have "Oculus app version 18.104.22.1686829". Is this what you mean by runtime.
Whilst I have Steam VR installed, I don't use it with P3D.
If you'll permit me to tack on another issue. When I resize panels on the Majestic Q400 using the "Resize Panel" command, the size is not saved, instead the panels appear squashed (vertically), I think to around half height. Using "Uniform Scale" changes are not lost, i.e. it works as expected. This is for changes in the same flight.
For permanent changes, is the only way to work out the position through trial and error and editing panel.cfg 3dp settings. Is there no way to get the values out after making changes in sim?