There is no "player driven" game save precisely for the reason you WANT there to be player-driven saves..... To prevent players from rushing into a deadly encounters with no sense of consequence because they could simply save scum and retry.

Instead of saves, the player should be using the provided game mechanics to deal with (or prevent) super long "death runs", and that is by setting up forward operating bases complete with portal, so if the player dies, while far away from home base, they can simply use the portal to cut out all that running, and be ported back to a close location to collect their gear.

Anytime a player goes out to explore, especially if it is to go far away or across the water to a new island, they should always carry resources for making a portal with them, and already have an available portal set up at/near main base to connect with. As soon as one makes landfall (after crossing the ocean) or reaches that far-away place, they should place the portal, which then connects them to their home base, and eliminates the long run to get back to their graves.