Hello,
I am not sure if I understand what is happening in your computers.
We are using the same method from the beginning, which is quite long time now (years).
I have to say that nobody had a similar issue as far as I know.
Normal situation is that you will connect the cable to your computer, start the unit, after initialization start the software and that is all. You do not have to tinker with any ports at all. This is how it should work.
If you can see that unit is using a different port than you can see in device manager than this is very strange. This could only happen if the software is running all the time while something/someone is changing ports in the operating system.
Normally the ports are not changing at all. On the same computer there should be same port.
The USB interface has Silabs CP2102 chip so that can be recognized in the Device Manager in the COMs & LPTs quite easily.
What could happen (with some notebooks under Windows) is that operating system has internal COM port for bluetooth device. This device is sleeping and basically is doing nothing and is unused. This could make a troubles with detecting the unit. Disabling this device in the COM ports can solve this problem (or turning bluetooth off or changing COM port to the higher number).
Each computer could assign different COM port, but that is normal. Once they are assigned the OS should remember how it was assigned.
Technically it should not be possible to see a different COM ports than these that are available and are not used.
If you can't see it then something is still using this port. Did you closed the software correctly previously?
Once you start the software, it will learn which port was used (where the unit is). It should always automatically detect the unit. So when you will close it and start again, it will directly try port that was used previously.
We do not plan to change the USB interface to a HID - this will cause incompatibility between platforms. We want to support as much platforms as possible. Current solution can work basically everywhere.
Maybe I dont understand the problem correctly, but for sure there should be none
So I believe that what is wrong can be resolved. The USB connection is the most reliable.