I thought about this when starting out with tcl; so I made duplicate partitions, and later made a rescue usb stick with all the stuff on it.
Still later, I finally realised that tcl is so small and modular there is no point in doing this. The only thing I have duplicated are a bunch of custom scripts. The rest is standard and tcl is small and modular so even if there is a non-recovarable disc crash or something, it is very fast and easy to set up again.
tinycorelinux - no backup needed, being small and modular. The best!