I’d like to add crop/rotate functionality to the iNat app eventually, but I think adding things like manual exposure and focus and other niche settings is likely not worth the development time. FWIW, in the current iNat iOS app’s camera you can hold down on the screen to lock autofocus and auto exposure, which is helpful for macro work. Then you just move the phone until your subject is in the plane of focus.
As for the import/upload part, the upcoming app has a much better flow for importing a batch of photos and separating them into observations, and should support share-to-iNat from your Photos app as well.