I have hosted at least a dozen Pulp Alley games at local conventions in Ohio and Michigan, USA, all of which were multi-player. All of these conventions had a four-hour time limit, which included teaching the rules.
I started out with scenarios for 4 players with 4 figures, but have tried 5 players with 4 figures and 6 players with 3 figures. All have worked, but now I always do 4-player 4-figure games. For me, 16 figures on the board works best and I would not recommend using more figures
unless you have experienced players. The Leagues I provide the players all have a Leader, Sidekick, and two Allies. I would resist the temptation to add any extras (Perks, Gear, etc.)--new players have enough trouble getting used to Abilities. I have used the Horror rules with success, however.
I have done games in Victorian Steampunk, Gothic Horror (including, in various games: vampires, vampire brides, werewolves, ghosts, and ghouls), Pulp Science fiction, and Lost Worlds genres.
Just for fun, here are some photos of a Lost World of Lemuria game I hosted at Pro or Con convention in a suburb of Detroit, Michigan on March 12 of this year. The scenario was Death From Above, which I have done before with Pteranodons as called for, but this time I used murders of crows from the Zombicide game.
Here in the final moments of the game Jennifer Jones (daughter of Indiana Jones), having obtained the Major Plot Point, has dispatched an Amazon and a Snakeman, and resisted attacks from the crows to claim a victory for her League.

Here are the Leagues:
Jennifer Jones and her League of Archeological Adventurers whom have "discovered" Lemuria. These were printed from STL files designed using Heroforge.
Imperial Lemurian League representing the interests of the Emperor.

The E-E-E-V-I-L Snakemen who lurk in the Lemurian wilderness.

And last, and not least, the Amazons of the Lemurian forests who oppose Lemurian imperial rule to preserve their traditional culture.
