So, my issue persists but I have been making attempts to correct it and have further observations.
I'm no long convinced the issue is the switches, specifically. That is, I no longer think they go bad prematurely or that this one button is going, possibly defective. The keyboard seems to work fine on my laptop but in the project which runs on a Raspberry Pi Zero (Raspberry OS Lite Bullseye) I occasionally get the issue, more later. That said, the switches may be contributing to the problem. I had found this issue before and have just re-confirmed it with my multimeter. The Kailh Choc switches connect just before engaging the "click," unlike Cherry MX switches which engage on or immediately after the click. It makes it possible to engage the switch without clicking. This is one of the trade-offs in using low profile switches, I suppose. I have V1 Chocs and do not know if V2 behave the same way, but would be surprised if they don't. So it might be that sometimes when I press a button that it engages a little bit earlier than I think and then goes into the key repeat routine a little sooner than expected, which would explain why I get double and sometimes triple hits.
Next I checked for mechanical problems. I was using the 48 key layout with a two-button space bar and thought I may be fat-fingering it. I don't know if the software would count each button as a separate button and not be effected by the debounce routine, but I suspect it would. I have replaced the two with a single button and have a stabilizer on order, but I was using it this past weekend and I started getting the issue for no discernible reason. I pressed directly down on the key and watched the space advance once when pressed and then again upon release. I have opened on of the switches and can't really see what would cause this double hit unless it's what I described in the preceding paragraph. The second mechanical issue is that I have the project is a case made of foam core, which includes a bezel around the keyboard. Since this case is for prototyping purposes, I don't care about aesthetics and the whole thing is held together with blue tape. I am constantly opening up the top, so the tape loses it's grip. This bezel has caused problems before with keys being hard to press because it's in the way, either lifting up or shifting out of position. I have it removed now and will see if I get further issues.
If I do, I will need to see about reflashing the firmware and extending the debounce delay. I've been reading through the QMK manual webpage and think I understand that I can simply add the config.h file to the appropriate folder. Would be nice if it had it so I could just edit it, as per the instructions, but such is life
