The Problem with Manual and Auto ISO 

I don't agree with beginners starting in Aperture priority. One of the biggest reasons for blurry shots seems to be too low of a shutter speed, and since so much of wildlife photography happens around sunrise/sunset, that mode is going to set the shutter speed too low very often (unless you manually crank up the ISO). I can denoise an image, but not fix blurry. I can see how full manual works good for you, especially if you have a dial set for ISO, but I've really enjoyed auto ISO with exposure compensation. For the animals I'm usually shooting, the overall exposure doesn't seem to change to quickly.

You can likely set your camera to lock exposure on shutter press. That way all shots in your burst will have the same exposure, making post-processing easier while still using auto ISO. This obviously doesn't work for sequences of single-shot images, but there's always the AEL button you can use when you don't want the exposure to change.

Canon offers the Fv mode. Imho the quickest way to adapt to the current situation. For beginners, aperture priority is often a trap because it will try to keep the iso low and therefore will result in too low shutter speeds eg for birds in flight. Beginners: decide for aperture, shutter speed and exposute compensation and auto iso to have the camera adapt to changing light and youre good to go

for me as a bird photographer my best results by far manual with auto iso always ..

You know, I've shot manual with auto ISO the entire year and a half I've been doing wildlife. I never really thought about the fact that exposure compensation (which I do with almost every shot) is basically exactly like changing ISO. The biggest upside though is that auto ISO gives you a good starting point and from there you can tweak to taste with exposure compensation. It also gets you a usable shot if something unexpected happens in a different lighting scenario, which is more difficult if you're full manual. Manual and auto ISO is the best of both an auto mode and still having total control.

I have noticed this myself when I have needed to focus stack that almost every shot will have a different ISO when in auto ISO. You can auto exposure match multiple images in lightroom but I only use photoshop so this would complicate my editing process to use another program. I just match the exposures manually which can be time consuming and it's probably never spot on. I can easily swap to manual ISO then back to auto so maybe i'll start giving manual a go when the lighting conditions are consistent but sometimes the sun is constantly in and out and I feel that I wouldn't be able to manually keep up with that.

I shoot manual with auto iso most of the time, but there are tricky situations where you need manual iso, and for cameras that have enough control dials and buttons it is an easy change back and forth. I can't do it as fluidly with Nikon as I can with Sony, Canon, and Panasonic prosumer/pro bodies. It's good to learn to shoot both ways and be comfortable with it. I would ride the ISO wheel way more than the exposure comp wheel, thus my choice. But overall, just do what you enjoy most and what gives you the least stress! 😂

Much prefer Manual with Auto ISO. I'm not going to edit every photo by hand, and certainly not everyone in a sequence. I have an auto edit applied to every image on import into light room to get a ballpark edit then I will cull through the images and typically only select 1 or maybe 2 images in any sequence to then edit further/modify by hand. Auto ISO will keep them all exposed pretty well and keeps me focused on tracking the subject and not exposure, and you really have +- 2 stops if necessary to lighten or darken a bird if needed, and then you don't have issues when the background is changing many stops that you will likely not be able to change the ISO fast enough manually to do. And if your trying to it's a higher work load. Everyone has an approach and do things differently, but I definitely do not agree with this approach, at least for me.