Support for Quectel EP06 wasn’t backported to LTS kernel 4.4 as you can see here.
However, the one line patch was backported to LTS kernel 4.9, and also for LTS kernel 4.14.
Right now for Turris 1.x and Turris Omnia, we’re using LTS kernel 4.4, which is supported until February 2022.
With Turris OS 4.0, we’re using LTS kernel 4.14, which is supported until January 2020. In a few months ago, we have released Turris OS 4.0 for Turris Omnia and Turris 1.x in early alpha state.
And looking about commit: USB: serial: option: improve Quectel EP06 detection, it was backported just to LTS kernel 4.14. So, with Turris OS 4.0 it should be better.
I’d like to know, if it works now before making any changes and all these commits are made from the same author.
I do not think it is a good idea to tape the pins. Specifically, the pins the user taped on another forum are the USB 3.0 tx/rx pins, so taping them will likely result in USB 2.x speeds.
This one is a little bit complicated. You can look for example here:
Some LTE modems are not detected by hardware, if pins are not tapped as it avoids pin incompatibility between PCIe data interface lines and the USB3 lines. For some users it can be enough to use USB 2.0 speeds, however, if you’d like to use USB 3 speed, you would need to have an adapter and plug it to the front or back USB 3.0 port.