I don’t see how a single INI SSU configuration file can change your device wakeup from suspend. I expect that reasons for should be somewhere else and unrelated to that package.
To uninstall, run in the terminal as root:
zypper rm sailfishos-chum
Unfortunately, you would hit then bug Ssu features are not updated on removal of the settings files which requires to some additional manual intervention for full removal.
I will write down later tonight uninstall instructions.