I know what you mean with glock ergo's, but not reaching the mag release without a slight grip alteration is common for probably 90% of shooters I know.
Even watching IPSC or IDPA shooters, most will do a flip to change mags anyways, and return to grip becomes second nature in your workspace. I've actually inquired into this and its suprising after a while that most people actually just flip and return properly anyways without even knowing it.
In short, don't worry about not reaching the release, practice your shooting and reloads and you'll probably find during fast reloads your flipping and returning naturally anyways.