I've given the one world Godlike challenge above a shot this weekend i.e. no colonisation permitted and for fun also no invasions (until later anyway). I'm currently on Turn 106.
As expected an Alliance Victory remained trivial. The only hiccup was the Snathi Revenge, since I couldn't produce very much, they saw me as weak earlier than expected, and also I was very exploration focused so had no military, so that took an unusually long 79 turns.
Around Turn 90 I finished exploring all of the anomalies on the map (including anomaly respawn). As expected artifacts have helped immensely and I'm now just 5 technologies away from a Research Victory. Obviously that will take a while with only 1 world but given the AI doesn't beeline to Research Victory technologies, and they are all under control diplomatically, it should be very feasible.
I have most of the Ascension Crystals, and while I'm in the lead the Ascension Victory type will of course be much longer away.
I just realised the AI only seems to use 1 survey ship! I explore the map like Distant Worlds, so I build more survey ships ASAP with a big focus on Thulium so can build tiny/small survey ships very early. With Ship Graveyards any ship found is retrofitted into a tiny/small construction ship or upgraded survey ship, which helps with range/relics/resources. If Frogboy could get the AI to copy some of this strategy it would make a big difference to the AI's exploration capability (although it should probably only be used on Gifted or above, otherwise the noobs will complain).
So seems on track to be able to get all the victory types. No reloads beyond reloading on Turn 79 and turning Alliance Victory off.