I really love the recall feature and have been in about a dozen games where it was used, sometimes vetoed, sometimes it went through, and it did it's job amazingly well every time.
Most importantly I have not seen a single base ctrl+k since I have pushed for using the feature in all the games I have been in and even when the recall was vetoed the players who voted for conceding continued playing instead of just doing nothing or leaving as they probably would have done in the past.
Just look at this game where foley and me voted to recall at min 9 (because it really should have been lost) but got out voted by our allies. So we continued playing and it surprisingly was a real game after that point.
This is a huge success and would not have happened without the recall feature! Foley and me would have almost certainly just left at that point, and then no game would have happened at all.
So not only does the recall vote stop trolls from taking the game hostage, it also allows the whole team to stay engaged, even in bad looking games.
If you make it a lobby feature, please make it enabled by default. Everything that's such a huge improvement to the game should be the standard, not the exception.
Alternatively: Make it a lobby option to specify if all or only a majority of players need to vote recall for it to pass, but keep recall in all games.
This doesn't fix the "taking the game hostage" problem, but it does ensure that voting for a recall will become the default first choice for conceding instead of ctrl+k-ing, which is still a huge improvement.
Recall, even if it doesn't work, is still a team decision after all, the exact opposite of ctrl+k-ing.