Can someone confirm that the Osmo works with the iPHone 7 Plus without any tweaks or overrides?

Yes, it does.

This isn't a great example, I'm new to this but 95% of this was shot on iPhone 7 Plus and OSMO Mobile.

Also some people have said that the iPhone 7 Plus barely fits but I have a 0.3mm case and a tempered glass screen protector fitted to my phone and it fits with at least 5.0mm to spare.