Posted this in the discussion on the ED forum, but thought I'd pass it along here too as it's going to be pretty buried I think.
This is what worked for me:
I reset my default head position to the old one. (rt CTL + rt SHIFT using numpad / and * to get the position I liked, rt CTRL + numpad 0 to save as default)
Then I modified the .../Mods/aircraft/A-10C/Cockpit/Scripts/HUD/device/HUD_param.lua file to change the value (Line 6) TFOV = 170 to 150. I did this from a copy/paste into my mods folder for OvGME so it doesn't have to be done manually after every update, but do what floats your boat.
My HUD is back to old cockpit visibility and is working just fine. With my old eyes, I also much prefer the old head position for reading the MFD's. As always, you may need to adjust a little differently due to your setup and personal preferences, and YMMV as to effectiveness, you may have to play with TFOV a bit. But it worked very well for me. Tested both with and without TrackIR with no issues.