Starcraft 2 uses a very linear command system. If you issue commands A -> B -> C (even in queue) you cannot then put a command in the middle and have it resume the previous set of commands. Anything new issued becomes the current set of orders.

For your transfuse scenario, you'd probably be best served by either ctrl selecting the queens (or have them in a separate control group altogether) and issuing commands to them while fighting and then going back to commanding the rest of your army as a whole (either F2 or the control group that has your entire army).

Starcraft 2 uses a very linear command system. If you issue commands A -> B -> C (even in queue) you cannot then put a command in the middle and have it resume the previous set of commands. Anything new issued becomes the current set of orders. You cannot insert commands into an existing queue.

For your transfuse scenario, you'd probably be best served by either ctrl selecting the queens (or have them in a separate control group altogether) and issuing commands to them while fighting and then going back to commanding the rest of your army as a whole (either F2 or the control group that has your entire army).