Yes. I use it for Channel, Bus, and Whole Mix.
Regarding Processing and Flattening. I would say always keep you 1 version Clean, 1 version Processed. So if at some point you want to come back in time and Re-Processed with less [something] you can do it. So i aways keep DRY and WET… As you only have 1 instance of the Analog HEAT available per project. But you can keep dry/wet, deactivate the dry, keep the processed version active (wet) and save the settings as a preset like Trk3-FM Bass. So when you want to come back you load your instance of HEAT, reload the preset and you can tweak it better then save, resample etc…
You can use Filter, EQ with the Spectrum to mix also…
But it’s kind of complicate i guess at some point you will only use for very special processing (distortion is one of it and all this crazy processing), Bus processing and Whole Mix subtle Processing and Maximise for you to listening or Play in gigs (before to send to mastering)
But of course as TAPE Drums Sample collection you can use it to WARM every Parts of your recordings