Changed 5V Micro to 3V, request assistance with ketch and bootloader

For months I’ve successfully used a self-built sim racing button box using your 5V Pro Micro - with an attached (wired) smaller box that handles three analog gauges - it uses a Nano. As I was having issues with the Ignition toggle switch not being a momentary switch, I recently changed to a 3V Pro Micro so I could use its 3v output to drive a FeatherWing latching relay. The hardware changes seem to have been successful, in that the correct blackbox LEDs and greybox instruments work as planned/desired.

After confirming the basic 3 v logic and 12 volt gauge connections, I opened the devices in SimHub. The Micro and Nano were seen in Device Manager, and appeared in SimHub’s compiler window…although the Micro was listed as "not configured’ (I believe that was the wording).

I assumed this was due to the fact that the new Micro had no sketch, so I made the mistake of loading the previous SimHub sketch that it had compiled last month (using my wiring & hardware info as input). After looking over the support sites, it looks like I damaged the bootloader: although SimHub reported it had successfully loaded the old sketch into the new Micro, the Micro stopped working right after that - it is no longer seen by Device Manager or SimHub.

Using SparkFun’s tech site, I tried to use IDE to reinstall the bootloader; it appears for a few seconds in Device Manager, and for about 1 second in IDE, but before I can accomplish anything the newly assigned Port disappears. I also just saw that other folks report they they have changed the Micro’s voltage and speed, but I have no idea how to do this. I never “told” SimHub or IDE that it was originally a 5v board, nor did I see how to inform the compiler that it is now a 3v board. I have very little programming knowledge, thus my reliance on SimHub. As this will likely be my only Arduino project, learning a new programing language is not on my bucket list.

Finally, I saw the note on your tech site about a fellow who wrote a bat file to “automate” the bootloading/sketch update, but could never figure out how to take advantage of this. Apparently the bootloading is done via IDE, but I don’t use that program to upload the sketches to the Arduinos - I use SimHub.

So, I THINK I need guidance on using IDE to correct the bootloading issue, and then I THINK I need to delete the current Micro sketch from SimHub and feed the hardware/connection info again to that software, so it can recompile it. I’m guessing if I do this it will “realize” the new Micro is a 3v board.

Am I on the right track?

Thanks