As a medic you generally only want one actuator spender on your LAS. Gamma Rays for single target PVE, and Quantum Cascade for everything else.

Because of that, in dungeons / questing I was continually opening the Ability Builder to switch them, which was fiddly and tedious. So I made myself a button to do it for me.

When QC is on your LAS it shows the GR icon, and vice versa.
When you click it, it will switch which ability is on your LAS, and assign the tier points that were on the old ability to the new one.

If both/neither skills are on your bar then the button will not be visible.

You can move and resize the button by click+dragging the thin border.

Slash Commands:

/qcgr- opens the options menu
/qcgr toggle - switches abilities on the LAS (same as clicking the button)
/qcgr lock - locks the button so it cannot be moved or resized
/qcgr unlock - unlocks the button
/qcgr reset - resets the button position and size to default

QCGR