No, it was due to a change to reduce flickering and speed up performance (as continually sending the updated IR to the PV has an overhead). For IR, it is best just to the use the VFB anyway - final renders will work equally well to either, if you have a preference for the native PV, but for IR the Corona VFB would be the way to go (is there any particular reason or benefit for you to having IR in the PV, btw?)