Hey Ricardo. It probably depends on which timescale you are looking at. For a given workout, my understanding from one of the first online sessions is that hRTSS is quite pivotal (basically using it as indicator of training load).
At the weekly level, the “Form” number for the week in the calendar view seems a good sanity check on how well modulated the training is (e.g., should be between -30 to -10 TSB when increasing volume, and higher than -10 TSB – or positive – on recovery weeks (from memory, Brian was commenting on it). I would then keep an eye on overall weekly volume (time or distance) and elevation gain for a general 10,000 feet view on how the plan progresses overtime.
I am sure there are many more (and anyone, please correct any. of the above if inaccurate!). But those are the main ones I keen an eye on. In the eye, I use metrics to check that I am indeed modulating the intensity through out the week, and the overall volume throughout the plan. Keeping it simple and not overthinking it. 🙂