Hi Mike,
2 years later... In the meantime the Mouse Scroll Wheel Event is implemented in LV2013.
Unfortunately we have to implement all in LV2012 in our SW team, and have a similar solution implemented as yours. We have also implemented a way to deal with absolute scrolling wheel values, this to be on the safe side. But the thing is, that when calculating with absolute values, a system with relative scroll values doesn't work so fluid with that absolute logic, as e.g. when having a previous value -120 and next value is 120 then the result is 0 and nothing happens. We first thought, that absolute scroll behavior is occurring only on old systems, but now noticed, that when accessing a PC by remote desktop a mouse scroll value is always absolute.
In the code you of your ScrollWheel example you give back both scroll values, the absolute and the relative one. Did you also implement a logic to detect how the system behaves?