I suspect the problem here is that the "pick" is somewhat bogus. The values were already determined BEFORE you made the choice, just as the result of the double feature is when you hit "gamble", and not when you pick a card, suit, etc.
Free spins are different, saving them can, in theory, change the result from what it would have been had you played them straight away. There is NO ADVANTAGE in this though, you are just as likely to miss out on a good run as you are to move from a bad to a good result by delaying.
There is a similar "bug" in the VP double game. If you press "gamble", but exit before selecting, returning to the game will remove your gamble option, having declared it as "lost". I tested this in free play, and found it held true for a number of attempts. Slots are different, there is no up card to start the feature, and thus no perceived advantage in quitting.
I believe the VP "bug" was to stop players seeing a dealer high card and attempting to withdraw without playing through the double game (advantage to player in this).
I have noticed recently that there has been a change in the behaviour of these gamble features, and this test may need to be redone (in fun mode of course!).
Leaving free spins pending MAY cause problems if the software throws a tantrum, as they are not stored in Playcheck, and players could find they had "lost" all the setups when they come to play them (Simmo!). There would be no proper evidence to reclaim the lost features from the casino, who will probably say "serves you right".
This incident with the treasure chests shows that this DOES occasionally happen, even though unfinished games and features are meant to be preserved.