Sounds like you leaned several good lessons. The aperture thing often stumps people because they think that with focus stacking they can open up to a sharper aperture - but it depends on your subject. I've had many people not understand why I have to stop down to f16 when focus stacking wither a macro shot or a landscape shot. However, even with diffraction at f16, the focus plane is still significantly sharper than areas within the 'region of acceptable focus', so for me it is still something I do for landscapes when I can. f16 on a crop is pushing it IMO, but still test it with different subjects and you will get a feel for what is worth doing and what you are never going to get looking good (in say a large print).
Sometimes you might want to just focus stack part of the flower and then shoot some shots at a much larger aperture to nicely blur the OOF areas - again experimentation is needed to get the right shots for stacking and blending (not necessarily for this shot)
The next lesson will be that even without wind, for a tricky subject like this, you will want to think about some way of automatically programming the camera to perform the stacking (computer or Magic Lantern - not available for the 7DII unfortunately) so you can easily collect 20+ images with evenly distributed focus movement and without touching the camera. In addition you will need a program to correct for the focal length changes with focus distance and stacking. I use Helicon Focus, which I still like and bought a lifetime license years ago, but I have heard Zerene stacker has become popular. I think there may be a free version of Zerene (8 bit, limited resolution or something similar). But unfortunately if you want to do this a lot, you will have to pay for a program to really do a good job. Even then, those programs have nice tools for manual editing.
Having said all that, there are still limitations, and sometimes you find you just can't do what you really want to do.
