There is also a limit of 32 abilities that can be added to a single command card, so keep this in mind. I found this out the hard way by needing 33 abilities (ONE above the max). You can spread the abilities to the various command cards, however. 3 command cards containing 11 abilities each (33 abilities total) works while 1 command card containing 33 abilities will not work.
If you find that you still need more space, a suggestion might be to create a do-nothing ability (of type effect-instant) and then have a trigger activate whenever the do-nothing ability is used that will select another (possibly invisible) unit that has high selection priority so you have access to the other unit's command card without deselecting your current unit. When you hit the 'cancel' button, it should deselect the unit so that you're back to your previous unit selection again.
@Antimatterthunder: Go
There is also a limit of 32 abilities that can be added to a single command card, so keep this in mind. I found this out the hard way by needing 33 abilities (ONE above the max). You can spread the abilities to the various command cards, however. 3 command cards containing 11 abilities each (33 abilities total) works while 1 command card containing 33 abilities will not work.
If you find that you still need more space, a suggestion might be to create a do-nothing ability (of type effect-instant) and then have a trigger activate whenever the do-nothing ability is used that will select another (possibly invisible) unit that has high selection priority so you have access to the other unit's command card without deselecting your current unit. When you hit the 'cancel' button, it should deselect the unit so that you're back to your previous unit selection again.