I did the same thing back in they day.

I developed on SCO (and, later, Unixware) on a PC, all of the clients were running the gamut of Unix OSes: HPUX, DGUX, AIX, SunOS, you name it.

Most of the time was spent on our box in the office, but I was constantly bouncing back and forth to client systems. Either on site, or over the modem. Having to juggle Termcaps and the whole thing. It was polyglot machine/OS world back then.

Just had to learn to get the best out of a baseline set of Unix tools. vi instead of emacs, awk instead of perl. Master those and never be left wanting on a new environment, so I can hit the ground running. No need to "bootstrap" (if the client would even let you, not always). Couldn't even rely on a C compiler.