Some real nice gear you haveThanks so much KAOS. We certainly do have the same needs. I've owned numerous Canon full frame cameras since the initial 1Ds. Now using the Fuji GFX100 system and a new XT-5. Still have my Canon 5DsR's and R5 with tons of glass. If you are correct that the M3 is as stable as the P4P, then I might see myself weaning myself off the Phantom series, though I still own a few. Yes, the pixel count is the same, but it's the quality and size of the pixels that really matters. I sure want less noise in low light. And I do a lot of panos, both horizontal and vertical, often ending with a squarish aspect ratio. I do use the Topaz tools, and have 28 years with Photoshop. You'll recognize my drone work scattered throughout my website.
M3 is much more stable than P4P and more stable than M2P. I'll probably sell my P4P and keep the M2P as backup...but I'm also interested in how good the IQ is on the Mini 3 Pro. If adequate, it would fit in a backpack with a good amount of other camera gear and might fill the need to have both systems with me. Sure I can put the M3 in one of my bags but less room for a couple of extra lenses, second body for timelapse, etc. Cheers!