Yeees! You’re right !
I have a r5 3600 and a rtx2600 and it worked for me !
I knew the tip about the Glass Cockpit setting to LOW but the second one (Instrument Heads-Up Display off) was new for me. So i decided to flight with this second setting to off, only changed it. And i saw it really give me more fps. I fact, i limited my fps to 30 in vsync option and with several planes over Paris, i dropped to 20 fps. With your second tip, my fps was 29-30 constant (even with heavy clouds in ultra, all the other settings are on HIGH ) even in internal view.
Good job !