Seems to be a consensus
Seems that most folks do indeed use an over powder card.
Most replies imply that they are using them for BPCR (by implication, rifle cartridges such as 45-70) , which I have also always used.
I expect that I will get the chance to try out my recent reloads with and without over powder cards this weekend. So I will see if there is a significant difference for pistol cartridges at shorter ranges.
I am now leaning towards home-making over powder lubricated felt wads, which may kill two birds with one stone, unless the lube migrates into the powder. I supposed we will have to see.