I suppose you're looking in the task manager on the start up tab for your boot times.
Not boot times. Only Post times. I am using a stopwatch on my phone to calculate the time it takes to get from pressing the ON button till I see the option (Del or F2) to enter the BIOS.
For some reason it's far longer than on any PC I've ever owned including other ASUS and ASRock boards.
I was hoping there might be a setting in the Maxiumus's BIOS to turn off checking the USB connectors for connected devices. Windows can do that once it launches. I tried turning off the USB checking but of course then it doesn't detect a mouse or keyboard and halts on the POST screen.
I will try turning off the CSM and see what if anything that tells me. Thanks for the suggestion.