I’ve put some thermal compound between the heated bed and the mirror.
I glued the corners of the mirror with a glue gun. It sticks perfectly and is still removable if needed.
If the glass plate is well cleaned (with isopropyl alcohol) PLA sticks perfectly (ABS doesn’t).
With blue painter tape it sticks even more.
The glass late increases the momentum. My drivers voltage is set around 0.5 V and it works fine.