Thank you so much for your experience, I am using 10 III and the paths for Polkomtel are slightly different.
devel-su mkdir -p /vendor/oem/modem-config/S185.1 echo -n "/vendor/firmware_mnt/image/modem_pr/mcfg/configs/mcfg_sw/generic/EU/Polkomtel/VLVW/Poland/mcfg_sw.mbn" >> /vendor/oem/modem-config/S185.1/modem.conf
The weird thing is even after creating that and rebooting, I still can’t enable it. Any further steps I should do? I will wait and hope it will start working, I hope if X10II worked III will too, but this phone was never sold by them.