If you read the FAQ, Captain Yorr presents us with another precedent. More importantly, it's a game rule that should probably be explored more thoroughly on its own. It presents us with two different scenarios:
Cost -> Effect, whereby paying a cost directly produces an effect (Yorr vis-a-vis Fel and Opportunist)
Trigger -> Effect, whereby a change in game state indirectly produces an effect (Yorr vis-a-vis Push the Limit)
To apply that here, the semantic distinction between "spend" and "remove" is meaningless. You manipulate the stress token to directly produce an effect. Fel's ability does not refer to either term, yet remains an obvious case of paying a cost to produce an effect. And, as people have already stated numerous times, Keyan's effect is universally handled the same way across all previous ships with similar abilities, regardless of the cost. There's absolutely no reason to believe that it should be handled differently this time.
Edited by WonderWAAAGH