There was also the commercial version from DKB called the KwikStartII which allowed the installation of 2 different KickStart ROMs and the ability to switch between them from the keyboard using the three key restart function. All that you had to do was to hold down the keys a little longer and you would then be started from the alternate KickStart ROM. All cold booting would be from the same ROM each time. Switching to the alternate ROM could only be done when doing a warm boot.
I had 1.3 and 2.04 installed in my A1000 for a long time, with a modified Startup-Sequence to detect which KSROM was in use and fire the correct User-Startup to use the correct HD partition for the corresponding AmigaOS for 1.3, or 2.1.
I spent many nights up late into the wee hours of morning on that Amiga. Great fun and memories from that time.