I think that this may actually be a bug... in terms of the quick search box anyway.
On mac, it can be removed in the same way as any toolbar item, just dragged away.
On windows, I just realised that it cannot, it appears to be locked in place (unlike the other items)
Thank you for the very quick reply. Indeed, I should have stated the OS is Windows.
Any update on the topic of globally disabling Quick Find? We have approx 500 layouts and going through them individually would be rather tedious (to put it mildly).