From previous post, I think an OCC, no ruins, raging barbarians would be a good test for a Science win at a relatively high level. Perhaps on a challenging barb heavy map like Boreal, Tilted Axis, or Frontier. Domination win not a challenge with these settings, Diplomacy win or Culture win would become a domination win for the most part. But Science would give leeway for different approaches with different civs, so an any civ approach would work here as well.
Go with a Science civ? Venice or India or Ethiopia who are helped in a way by small civ? Shoshone get neutered with no ruins... Spain as always a contender for any civ win? Military civ to dominate AIs and extort them? Aztecs for possible floating garden and culture kills? Egypt for wonders?
If you didn't want to go "any civ", I think Egypt (wonder choice), or Sweden (friending/great people options), or Aztecs (sacrifice on a massive scale), or Byzantium (religion choices) make for the most interesting gameplay with this.
Any level from Prince to Immortal would work (Deity would get so few entrants), but King or Emperor probably best. AI civs need to be tough enough to challenge the player and high enough level to be able to be good trade partners/tribute payers. Having a chance at good wonders would be good, so Prince might be cool but AIs may not handle raging barbs well at Prince, while Immortal would make the challenge really stiff. King or Emperor probably sweet spot. Standard size to give the AIs a good run? Small size would make play time shorter though and allow for multiple games in the any civ format, so that may be better. Just floating ideas, but making it tougher on players by specifying the "increase difficulty" checkbox options is the general gist.
Edit: the more I think, the more Boreal should probably be the map choice for these settings. Almost no "great" initial setup possibilities with Boreal, so feeling you "need" to map reroll not an issue Boreal also definitely has the most wicked barbarians for some reason.
Maps like Tilted Axis and Frontier and Highland will have small pockets of awesome terrain, so rerolling a lot of maps would be a thing if you wanted a great game. Might not be ideal. No water maps for sure, as raging barbarians is not a challenge really with water. And everyone has more Pangaea games than any other map type so no need for that.
With an any civ approach on OCC Boreal, I would expect Spain to maybe be the obvious choice as natural wonders largely unaffected. Korea or Aztecs or Siam could still be contenders I think.
So I propose Science Victory, Boreal, King or Emperor, Small map, Standard Speed, OCC, raging barbarians, no ruins. Either "any civ"or 1 of the 4 mentioned above (Aztecs, Egypt, Byzantium, Sweden) Feel free to tweak or make suggestions if this could be improved.