Fulminato
I wouldn't say the best route at the second gathering is as clear as at the ardford summit.
It is likely that the established plan with light collateral, perfect succubus council, freeing the champion and attractive orcs will be the best, but there are a few close contenders.
For example I'd like to boost sapience for orcs over attractiveness as personal preference and can dream about that giving future mechanical advantages. (Orcent comments about Tak'Kan that "the societal fortitude of our allies there will soon be tested." that means a sapience check, right? 😛)
You can get sapient orcs, light collateral and perfect succubus council if you go with the original orgy plan and use one investigation slot to map the tower. The orgy plan is basically just an RP loss, we could find out in the future, that it does not matter if Ginasta can be maxed anyway and we make all Xestris checks. We can probably find an investigation that doesn't have terrible consequences if we skip it. So maybe this path will turn out to be better.
We don't know how important philon cooperation from the succubus council and philon influence will be. Maybe it will be worth it to skip that in order to avoid all collateral damage and collect some country scores.
The established path is probably the best, but I can still see it changing depending on future events.
SotterPapaioannou
You also get Mestan RP in the Finale, up to 5 for having 20+ Victory Points. As far as I can tell, you can't send Mestan to the airship if you want to max him without sending the orgy succubus his way.
The best plans for getting the orgy Mestan RP I found involved killing the orc champion, to gain gathering influence or to enable me to throw to Nalili for the Orgasmic influence. Alternatively I could let the orgasmic empire keep its current slavery policies. Which I don't think is worth it, just to gain the ability to send Mestan against Fuzkao.
But I had fun looking for plans for the gathering, so if you think you'll enjoy the process, go for it. Maybe you'll find something good ^^