At first pass, it seemed to me that Grappling Struts only offered Vulture Droids one means of intentionally leaving an asteroid or debris cloud on which they had parked: the 2 forward maneuver. Then I remembered that while sitting and spinning on rocks, they still get actions, including barrel roll. They can barrel roll off the obstacle! On the following turn, the language about not executing maneuvers is conditional on being range zero of an obstacle, so you could execute the maneuver you selected. Barrel rolling off an obstacle is a substantial increase in their options mainly because the firing arc is now perpendicular to the direction of travel, rather than in line with it, and you could rotate 90 degrees before performing the barrel roll. Being able to get off the rock in 7* different ways, is a lot better than only one way.
* 1) two forward 2) no rotate, br left. 3) no rotate br right. 4) rotate left, br left. 5) rotate left br right. 6) rotate right br left 7) rotate right br right
Your next maneuver would execute as normal and you would then flip the card back to the closed side. What I have not thought through exactly is what happens if that first maneuver overlaps another obstacle. I think it would flip down after executing, but then on your next turn you start on the obstacle with struts closed. I suppose you'd move from that position as a normal ship would, only having the option of parking on that obstacle if your next maneuver kept you on the obstacle (albeit in a different position).
It just occurred to me that while parked with struts open, your barrel roll might not take you off the obstacle. So, you could kind of waddle around on the same obstacle, if you wanted to and your rotates and barrel rolls kept you on it.
Edited by matt.sucharski