When adding ScoreTimerModule to the Pack and the steps parameter value is negative returns an invalid output command.
To explain shortly, I'll show examples. Below I have the module widget placed in the modules parameter of Pack.

Building the pack with the ScoreTimerModule should create:

However, the module creates an invalid command:

The solution to this error is to use the modulus operator on the steps parameter in the constructor:

This fix should leave positive values unaffected as it is only setting negative values to positive.
If you'd like me to implement the fix I could contribute to the repo, however, I've only started teaching myself how to contribute to repos owned by others.