I don't disable secure boot. It has its place. If you are using boot media that supports it, you've got no worries.
I have a WinPE that is built with 8.1, supports secure boot, so I can service machines no need to fuss with settings.
You never know what settings go wrong with disabling secure boot. On some systems like HP, it can prevent activation as activation on some units relies on secure boot keys being OEM, which are deleted when secure boot is disabled. Granted, these may be rare cases, but in general I try not to mess with EFI settings.
We were talking specific OS that have quasi EFI support. For 8 and above best to leave security settings as they are.