FlameDuck and AngelDaniel are right. Primarily the hertz is the rate at which Flip returns control to your program and if Blitz decides that your monitor can handle that refresh rate, then it will use that, or pick (not the closest match, as it should be) the first refresh rate that comes up on 'the list' (presumably video driver feedback), usually 60.
So setting the hertz in BMax -is- foolproof, SO LONG AS your drivers report correct refresh rates for your monitor! The Windows 'Plug and Play' or 'Default' monitor drivers generally lean more on the conservative side so if you have them you 'should' be fine. If you have manufacturer monitor drivers which are just wrong there is nothing you or BMax can do any better.
If you use 0 to set your hertz, BMax will use your desktop's refresh rate, but then of course you will have to find helper functions to recover that refresh rate if you need to know it.
So setting the hertz in BMax -is- foolproof, SO LONG AS your drivers report correct refresh rates for your monitor! The Windows 'Plug and Play' or 'Default' monitor drivers generally lean more on the conservative side so if you have them you 'should' be fine. If you have manufacturer monitor drivers which are just wrong there is nothing you or BMax can do any better.
If you use 0 to set your hertz, BMax will use your desktop's refresh rate, but then of course you will have to find helper functions to recover that refresh rate if you need to know it.