The most comfortably I ever saw a person wield the telnet/rsh/ssh escape sequences was when I was an intern, visiting a Cray division, to port some software. He was juggling multiple hops, to get to a machine across the room, with the panels off.

I'm guessing that juggling multiple hops might've been ordinary in Internet-based supercomputing center practice at the time. Including through terminal servers?

Though it would've been aesthetically cooler to sit at the console of a front-end processor of a Cray or Connection Machine. https://en.wikipedia.org/wiki/Maxell#/media/File:Blown_Away_...

(I ended up creating some multi-hop-to-go-10-feet situations myself at that company, such as for crudely gatewaying from our main Sun-dominated engineering LAN, to some porting systems, such as VAXstations that were only on DECnet. Half of the engineers had been developing things like LAN-accessed in-circuit emulators, borrowing other workstations' tape drives through rsh as part of a local Unix command pipeline, etc., so they were also unusually comfortable with the hops.)