Uplay so they're tied to your account but they're in the folder Uplay is installed to and then savegames and then a folder name around a number which for this game was 1200 something I believe, differed a bit in the beta and then it will differ between Uplay, Steam and Uplay+ though if it's the same account a copy/paste might work but it might also not be compatible and I am pretty certain the same as prior games is also used here so other saves won't be compatible.
(Earlier versions could be edited to add in your own ID but I don't think that works anymore.)
EDIT: So I guess a early unlock of the raid content isn't easily achieved without a few hours. Level cap is 30 and the last skills are from taking out the Behemoth things (Tanks that dodge ridiculously well.) and getting the skill point chests these guard (They just have these in chests for however that work.) and then for the level scaling itself other than higher numbers going from white to green to blue with still more bonuses but still low overall numbers it doesn't mean much.
Even at level 1 and gear score 1 it's entirely possible to walk over to the base where Walker is and just shoot him in the head and win just avoid the drones where gear actually makes a bit of a difference but for humanoids a headshot is all you need regardless of some number on a piece of equipment.
(Makes no sense and the story gets kinda broken and the guy probably still shows up because no one would ever go out of order of events apparently though it's fully possible to hit level 20 and a gear score of 150 - 200 in a few hours just doing random non story stuff too and then cap Walker as the first mission undertaken in the game.)
(Bit of a spoiler though not much of one but essentially taking out a priority target and how it can be done nearly immediately although unlocking Nowhere first the little cave hub of every other Nomad is recommended first.)
EDIT: So beyond the raid and not being able to start that without gear score of 200 anything else is just available and the main mission saying 150 can be done anyway either interrogating or just heading over to the obvious area and finishing the fight pretty quickly.
EDIT: Hmm thinking of it assuming there's no other hindrances the table and just god-mode and getting to Golem by way of lengthy sea trip might actually work too for just getting the exclusive items in that place but just a theory really haven't tried yet though at least the BZZZ and drone swarm warnings aren't as bothersome now that the rest of the game is open for exploration ha ha.
(Guessing the other fogged islands on the world map are future raid areas then and Golem up in the corner off the distance discouraging manually just flying there via helicopter.)