I tried bootrunner yesterday on my MacPro 5,1.
SIP is disabled.
It has MacOS Mojave an MacOS High Sierra on same APFS SSD and Bootcamp Windows Legacy Mode on a second HD.
If I set “undefined” in Other Options it can boot to Mojave and High Sierra but not to Windows.
If I set “Legacy” in Other Options it boots to Windows and Mojave, but if I click to High Sierra it boots Windows too.
So it seems, it can´t discover boot style.
Is there a way to set a different boot style for every single Installation?