RB951-2n behind CGNAT - What are my options

So, running a old trusty RB951-2n and today found out im rocking the awesome CGNAT experience.

So, I am wondering what my options are. I was just trying to setup a simple PPTP VPN but now, no go.

I read about ZeroTier and MikroTik support but see that there are not many hardware models that support it? Are there any alternatives or any way I could run ZeroTier?

TIA