Still trying to get the correct focus. I'm using Live View and digital Zoom to do manual focus since I have no Auto Focus with the tubes.
Thank you for the kind words about my images & I did try to use a little rocking back & forth to help focus. I am using a 70 - 300mm lens with the extension tubes.While it can help a lot at close up scales, I've not found AF useful at all for macro. With one of my setups the entire focusing movement from the marked infinity to MFD works out changing the focus distance from 125mm to 120mm. Adding this limited range to the possibility that the AF picks the wrong bit of the subject.makes AF pure frustration. In most cases gradually changing lens-subject distance (rocking back & forth to finish) works much better.Using a focusing rail on a tripod is ideal when the subject is static - but I find thats rarely the case for me so I often end up using flash.
I wouldn't worry about the lack of AF with your tubes unless your using much longer lenses on them, with a 200mm lens on my MFT tubes AF can be handy, but this is a long way from macro.
FWIW Your last 3 images in the opening post are IMO better than I manage to get for the vast majority of my macro efforts.
I have been using a tripod & I'll look into stacking, & yes I almost always shot in RAW