probably known. as soldier plant a C4 then switch to engie and plant a mine on your c4 which is still there.
so C4 should probably disappear on switch.
plant c4 switch class then mine
iwound
(iwound)
#1
Protekt1
(Protekt1)
#4
Should remove the ability to have a mine and c4 down at the same time. Have the c4 take priority.