I enjoyed this and did not find it a slog. There is a (very narrow) chain of logic that’ that leads from the start to the end and avoids too many repetitive calculations. This relies on using each piece of information that we are given at the appropriate time to make the next logical step.
I have now solved it three times and each time I feel I have gotten nearer to the “ideal” path from start to end. A very nice construction with *just* enough information provided to make it solvable.