I just had my electric panel replaced a week ago and I'm up to 12 devices detected. I has my data reset about the same time as the firmware upgrade, so it's hard to narrow down the improvement to one or the other, but this has been MUCH faster than the previous detection. I think it had about 15 devices after a month of usage on my previous panel/firmware. I had one of the terrifying Federal Pacific panels that so often have defective breakers, so I wonder if the quality of the breakers themselves has any impact on device detection?
Another change has been the weather this week. We've been using fewer devices (mostly heat devices) since the weather has been warm. It could be that with fewer devices running, Sense is having an easier time detecting unique signatures?