This maybe isn't new technology, but it's a collection of some ideas that I like along with some additions of my own. I'm using jbkuma's aviation plug for interchangable blades and Kolgrima's Brewboard.
I received some DF Player Mini knockoffs that didn't work properly, so I decided I needed a way of trying components and new ideas before putting them in a new saber. I put sockets on a Brewboard and attached a test saber to a piece of plywood with a breakout of a few extra pins to a breadboard.
I'm using a pullup resistor on on the Neopixel data line when using a Star LED blade and checking the status of that pin on startup to see if the correct blade is inserted. I'm also checking the voltage to see if it is running on USB power or battery.
The programming plug has an RGB LED and a single Neopixel and can be switched between the two blade types as well as between battery and USB power.
If anyone is interested in using this, I have schematics and code I can share.
Demo video of the testbed in action.
Video showing the reason I wanted a testing rig.