For whats its worth the mednafen port, for me has better intergration into retroarch, for example states and runahead. I have looked into the core a few days ago, added some few minor updates for better homebrew(BS93) and support for headerless roms. also added screen rotation using select button (might move this into core options).
If anyone still loves their Lynx days, feel free to post issues you are having, i may, in my limited coding experience, could do something about it. or someone might have an interest with it.