After bricking a few units I finally sat down and read the manual for my SparkFun Qwiic Pro Micro - USB-C (ATmega32U4). I also figured out the cause.
The cause of my unit bricking was bad code. Compiled and profiled fine, but crashed the unit when uploaded. As a result the port became unavailable and seemingly gone. In my particular case one brick was via and unsupported command in my source. The second brick was abuse of memory. Sketches would upload, then the unit dies and the no connection message pops up.
The solution for this unit was use of the reset switch with some key timing, and a trusted script to recapture the device. This page was all I needed to read, classif #RTFM syndrome.
The following is a layman version of events for those less fortunate having not endured decades of software brain melt.
Recovery in a Nutshell
The USB port/comm when working will/can flip between the "normal" mode and the bootloader mode. Bootloader is a mode where the devices is exposed and can receive code and special commands.
If something, like the code, is causing the device to crash, such as I had, then the desired USB/serial port is not available.
The Reset Switch
The reset switch may also be some pins to be shorted. The manual talks about high/low and resistance. Generally I have found you just short the damn thing, milage may vary. I used the button.
Per the instructions you can double tab the button and then I seem to trail off and not really absorb the rest. Eventually I got the pattern.
If you double click the reset button the device goes into boot loader for 8 seconds.
Find a short "hello world" sketch and have it ready.
Double tap the reset button and immediately upload the sketch.
That may not work...
When uploading a sketch the beginning of the upload is the compile step. This must complete before there is anything to ship to the device.
I had to click upload and then double tap and get the timing right. Eventually I would use the shortcut (CMD/CRTL + U). The sketch takes and the device is back to normal.
Hope this helps someone - I needed the dummy version.