I've had mixed results. One figure with dents in several places (similar to your Power Droid) on the bubble was very accepting of being squeezed back into shape. It didn't remove all the dents but did significantly improve the appearance of the piece. This was an ESB Yoda with a slightly yellow bubble.
Then I've had SW bubbles where the squashed corner is hard as a rock and just won't budge. No improvement but no additional damage.
Then there's the worst case scenario: I'll just push this corner slightly to get it back into shape... zip... bubble seal opens completely along the left side from top to bottom = loose figure with cardback
I'd say the last result is a rare and unfortunate example. I'd always be prepared to try and coerce a bubble back into shape. You should be able to tell quite quickly whether the bubble is still pliable and would reshape easily or if it's going to stay like it is. Be gentle, look for other flaws such as very yellow bubbles, a weakened bubble seal, micro cracks, etc. and be gentle
Oh, and don't try to use a hair dryer to heat the bubble, that will only end in disaster!