I don't think it's quite as clear-cut. MPs are meant to vote according to their conscience, not party lines or coalition agreements.

It's a choice to vote against what a party claims to be their values in order to maintain stability in the coalition. The smaller party could also take a chance knowing the larger party won't abandon their comfy government position over it.

It's also interesting to figure out which values or plans a party has been willing to compromise on, since none of them publicly state this before elections.

I feel like these tools work best if you just use them as an additional data point in your decision.