So, let me just try to get a clearer idea of what you're asking for.

Are you hoping instead of just games advertising for players, players advertising for PSL partners, or players asking for game suggestions, that there could be a section where players could also advertise as players of certain characters seeking castmates?

Because that is a potentially good idea. The PSL section is very similar to that, given how many people look for castmates for PSLs, but having another similar section and it'd just be geared towards people searching for castmates for games insteads of PSLs might work.

Maybe organized just like the PSL section? People could name the canons in their subjects and then talk about who they play, what games they play in, what cast members those games already have, and who they're looking for. The "wanted" sections in the game ads do perform that task a bit, buuuut tbf they can be a little impersonal. Sometimes people are looking for a cast to join but would want a chance to talk to the players first.

Is that basically what you're looking for? A section like the PSL section but for luring castmates to games?