I have to say I really love KSM. I have installed it on 3 kobos i had anfd never dissapointed me!
Today I updated my kobo libra's firmware to version 4.25.15875 (09/nov/2020) using KSM9 and after this my kobo could not load KSM anymore, only nickel.
I tried a fresh full reinstall and did not worked for me, so after some hours I have decided to opt out to use KSM anymore
Finally I got lucky using the "new" semi-automated installation method created by NiLuJe and Koreader is running again into Nickel...
¿Is KSM dead? Long Live KSM!