@NB - Re: Priorities?
I especially loved this paragraph:
Note: Windows 8.x+, including Windows 10, will overwrite any UEFI choices you make and install itself as the priority boot choice after every boot. Changing the boot order in the UEFI firmware will only last until the next Windows 10 boot. Know what the Change Boot Option key is for your motherboard.
To make Windows 8.X and above respect your boot order, you must enter a Windows group policy and have it execute a batch (.bat) file on startup.