46mm Webers with modified progression

[1QuickS]

I would like some input regarding experience using 46mm Webers on the street and that have been modified to have the "slit" progression circuit vs. the traditional drilled progression ports. The slit has been used in race applications however I need info regarding suitability for street applications. I provide a picture of the "slit" progression and of a 46mm throttle body that had the "slit" removed and four hole progression retrofitted in its place. The throttle plate with the slit progression has been drilled to help allow more air at idle to overcome the richness of the progression at small throttle openings...my belief.

Slit progression showing large air bleed in the throttle plate:




Four hole progression retrofitted into throttle body: