For Sense, simpler is better. Single and two-stage compressors are likely easier to detect than multi-stage or variable speed. And from what I infer from the article below, heat pumps and mini-splits also fall in to the more challenging category. I have two single-stage units, one a 3 ton and one a 4 ton, and both have been detected.
Feedback from Ecobee thermostats could help. Sense has an integration with Ecobee that feeds your thermostat heating/cooling history to Sense, which should help with creation and improvement of AC models.