awiouy I begging you now for help! I know you mastered all those things as I've seen your posts from years back about tinc...
After couple days ofr esting from it I'm back with new ideas
Managed to get my own config like you said using "$DIR_LEGACY" in your tinc.start
So far so good. I'm connected and vpn ip works (can browse 10.0.0.1
Need to add my home subnet and if possible have my home ip address as main mobile ip.
Here is my tinc.conf