Hmm, thanks, I'll have to keep an eye out for whether I get compilation issues for anything important enough to warrant doing something about it. Good to know however, I wasn't aware of this thanks.
No need to apologize, the fault is my own. I assumed GPT based on my prior reading, all of which suggested that UEFI doesn't work without GPT if only due to never mentioning the alternative. This is however excellent news, it greatly simplifies the entire setup!
So looking at the image you suggested, I noticed the two bootloaders in the EFI partition, but nothing on the main partition. Is this because the loader for normal MBR boot is written in the PBR of the main partition? Also incidentally it occurs to me that I'm assuming there is boot code in the MBR /and/ the PBR, is this actually correct?
Further, does this then mean that the MBR boot code is agnostic of whether the machine is 32bit or 64bit or am I still missing something in this regard?
In terms of practical installation of this system as far as I've been able to pick up from various sources the process goes something like: fdisk (EFI and NetBSD) -> disklabel (for the NetBSD slice) -> create the filesystems, at this point the NetBSD guide becomes a little fuzzy. I'm guessing one writes the MBR bootloader into the MBR and copies the EFI loaders to the EFI partition (I remember something about a "mbec" folder containing these, but I'll have to check to make sure). Is this high level overview reasonable?
I suspect one could pick either MBR or EFI to install during the installation process and then set up the other as a post install step if sysinst cannot do both during the install process which may simplify the process.
I have a few other questions at present, but I need to read the documentation first so I'll leave this as is for the moment.