As has been noted above, at this time if you want to fully remove a single or multiple smart plugs from Sense, you need to remove it from its respective app and then turn the integration off (and on again) in Sense. Yes, this means you will lose your data for all smart plugs (you can grab it beforehand with data export, but I know that’s less than ideal). The other option is to simply rename the plug (that’s what I’ve been doing), but the drawback there is that the historic data will not be accurate. In short, we understand the neither of these options are ideal. We do plan to add individual plug deletion in the future but, admittedly, smart plug adoption has not been very high and thus there are more pressing dev priorities.
As we’ve discussed elsewhere, yes, this is absolutely something we’re working on and was a big impetus behind the integration. That said, it’s not something we can instantaneously add. It requires a lot of Data Science labor to get us there. The good news is that we’ve made a lot of progress with the smart plug data we’re getting and still plan to roll out a feature like this in the future. It is not right around the corner, but we’re actively working on it.