I haven’t run the adventure at a convention at all, though I have run it on one of my gaming groups as a test scenario for the game back when it was still in Beta, but…
“Mind Merchants of Mars” would likely work pretty well for a convention scenario, but there are two provblems with it. First is the fact that it’s an open-ended scenario, meant to be the first salvo in a campaign. If I were to run it for a convention, I’d want to give it an actual solid ending so that the players weren’t feeling left down by the ending to what would really be a one-shot, rather than a campaign entry point. Second, the fight to escape the guards at the beginning could take longer than is best for a 4-hour scenario, especially since you also have to spend say 10 minutes explaining the game rules and mechanics.
Virginia of Modiphius ran “Mind Merchants” on the in-house gang at Modiphius in a set of four, roughly one-hour videos over on Youtube. I know that I plan to borrow the set-up and basic plot she ran for my campaigns.
That said, another option would be to write a scenario for a convention game. The adventure generator in the Narrator Toolkit might be good for doing this. I’ve already generated a couple of basic stories for my gaming campaigns this way.
Hope that’s been useful.