Automated SW testing on different Raspberry Pi models?

I'm currently working on a side project - a bare metal version of Smalltalk-80 for the Raspberry Pi (see [1,2]). Even though this is just a fun side project, I would like to support as many Raspberry Pi configurations as possible. Accordingly, each software version should be tested on all available Raspberry Pi variants (Zero W, 1B, 2B, 3B, 4B - I know there are more, but that's what I have here right now).

Writing an SD card with the boot image and then swapping around the card, HDMI, USB keyboard/mouse connections and power between five different Raspberry Pis is suboptimal and probably not that healthy for the connectors in the long run, so I am looking for a better solution.

So, if you are using a test environment for different Raspberry Pi versions, I would love to hear about your hardware/software setup (e.g., HDMI/KVM switches, SD card with network boot, ...) and experiences.

[1] https://www.linkedin.com/pulse/relive-part-xerox-parcs-history-smalltalk-80-raspberry-michael-engel/ [2] https://github.com/michaelengel/crosstalk