Well, maybe a boost referenced switch, but somewhere high like over 30psi? is that high? I have zero experience other then what folks have written with spray and diesels, and not many talk. when can you bring spray on?
I've managed on several occasions to get "blocked" by the trans on the shift and my foot hits the floor, if it was "WOT" triggered, I would of sprayed with zero load on a miss shift, if only for a brief second. I'm sure that can't be good.
As far as boost references, I can make 50psi and not be at WOT, but what really is "WOT" on a diesel, since there's no butterfly plate and fueling amount is well, not metered by an air flow restriction devices (butterfly)..., Maybe combo of both?