"My name is Ozymandias, king of kings: / Look on my works, ye Mighty, and despair!"
Habeo in animo vivere in perpetuum aut mori dum conor.
I can't see anything specific on this, and some of the posts imply that you MUST play Gathering Momentum cards in the action rounds. However that is not what the cards say - they say that they can't be played during the Campaign Strategy phase. Our interpretation is that this means that if you use your candidate card or say, draw 2 cards, you can then choose to play another card while retaining the Gathering Momentum card (and then discarding it) as you aren't forced to play it in the Campaign Strategy phase. The only way that I can see that we could be wrong on this is if "discarding" counts as "playing" a card, which is a bit strange.
Can you please confirm or deny!
Yes, you're correct. If you use your candidate card or use an event to draw more cards, you may end up not playing GM. This is how the Wargameroom program handles it.