XK05, FK05, MK05 - anyway to separate block/unblock?

Does anyone know if there is a way to separate the block and unblock activities for transactions XK05, FK05, MK05, etc.? I believe they are controlled by auth objects F_LFA1_* and ACTVT 05 (Lock). I have a request that a role be able to block a vendor, but not unblock. Is this possible?

Thanks.