Yep, location shoots are messy, crews dont run standard shifts, lots of o;vertime and complex penalties.
Decimal time keeps it clean for time and and half, double time, like 12h48m becomes 12.8 so base for 8.0 then 4.0 at 1.5x and the last 0.8 at 2x.
Would your value ladder include sub cent units so these splits pay out exactly with no rounding fights :)?