BrotherCut

So we have Brother MFC-L6900DWs that have built in card readers on them and they are going into multi printer systems that already use paper cut and badges. External card readers added allegedly will work with paper cut on these Brothers but some say the "built in" reader will not work with Paper Cut. But I don't know why it wouldn't. Looking for insight or anyone who has dealt with this? If it cant work we will have to add external card readers to every brother devices that come from the factory with built in readers..... Which is just insane to me... This video shows it works... Video of Brother MFC with Papercut

So we have Brother MFC-L6900DWs that have built in card readers on them and they are going into multi printer systems that already use paper cut and badges. External card readers added allegedly will work with paper cut on these Brothers but some say the built in reader will not work with Paper Cut. But I don't know what it wouldn't. Looking for insight or anyone who has dealt with this? If it cant work we will have to had external card readers to every brother devices that come from the factory with built in readers..... Which is just insane to me...