"getting access to the JTAG pins"

I have seen some of the boards being reflashed with DirtyJTAG and openfpgaloader.

JTAG pins might dissappear from the board?

There is a video here "Pico-DirtyJTAG: Cheap JTAG Programmer! Raspberry Pi Pico for Lattice ECP5 + Icestudio":

https://www.youtube.com/watch?v=Yj1X4PIoQGg