I don't know if others have already suggested this, but how would people feel if after a certain level of a skill, you can gain a new ability? The one I was thinking of is after level x, you can build and use tools while swimming.
It makes sense that we aren't able to immediately use tools while in deep water because I suck at swimming irl and I'd struggle with that. But I feel like after learning to swim better, it's more feasible for the player to be able to use at least one-handed tools like a hammer or knife and swim with the other.
It would also make for more cool water building potentials in survival mode. Maybe even after level x+n, you can dive as well to pick up dropped materials under water or add support beams for bridges. I don't think it'll be too far from vanilla and just adds to the experiences of the game.
Source: https://www.reddit.com/r/valheim/comments/sj3dat/leveling_up_swimming_and_using_tools/
