You mentioned you wish to become NAT unrestricted. The other members told the snowflake proxy does work with restricted NAT and it does work no problem but you will only have small connected clients. But if you still want to pursue then go for it. If you have time may I suggest you check out my post.
Especially the part with the NAT behaviour discovery using STUN
https://forum.torproject.org/t/standalone-snowflake-nat-type-problem/16246/6
Hope this helps and just reply back if you’re still stuck… let’s make that snowflake BURN! 