Here's a clip. (Apologies for the lousy framerate; actual gameplay is smoother than that.) This was recorded using the latest nightly.
The Tribune explodes 21 seconds in, then the Irkalla deploys its Gorgons. Irkalla itself is already targeted. Cancer 1 deploys from the docking bay on the Irkalla's left, on the opposite side of the ship, while Cancer 2, 3 and 4 emerge from the docking bay on the right side, nearer to the player. The H key is pressed several times, targeting the following units in order:
- Cancer 1 (~2800 units away)
- Cancer 4 (2400 units)
- Irkalla (3100 units)
- Cancer 1 (3000 units)
- Cancer 4 (2200 units)
- Cancer 2 (approximately the same distance)
The system appears to be prioritizing Cancer 1 and the Irkalla, even though they are at all times more distant from the player; Cancer 2, 3 and 4 are clearly closer.