MH> Mystic can do a double telnet back to Mystic.  That is the only working
 MH> example that I'm aware of at the moment.  Looking to see if there is a

I believe the way Mystic works is that its behavior varies depending on the
connection circumstances.  For example:

If you are connected via a telnet client and you do an outbound telnet, then
Mystic knows that your telnet client can handle the telnet negotiation, so it
connects but passes any telnet negotiations directly to your client and any
response from the client directly to the outbound telnet server.

But if you are connected via SSH or RLOGIN and you do an outbound telnet
connection, then Mystic knows that it must translate from telnet to SSH/RLOGIN
and it will handle all of the telnet negotiations so they never reach your
client (because your client won't be able to handle telnet stuff).

--- Mystic BBS v1.12 A46 2020/06/11 (Windows/64)