I think there are quite few things that we could have in haven and hearth from Dr.Stone anime/manga.
https://dr-stone.fandom.com/wiki/Invent ... iscoveries huh also helpful wiki/fandom guide too, to see what fits the hafen settings and what wouldn't fit.
Stuff as simple as soap bubbles curiosity, has random mid/high chance to spawn when using soap/picking up/holding soup, rarer bubles like big bubbles or multishaped or other.
Traps for trapping animals that you could otherwise just pick up and won't fight back, but could be like determined by quality, if animal quality is higher than the trap, the trap breaks and disappears/despawns, if it is higher quality than the pray that happens to have its walkpath over it, then it traps it and waits for you to pick it up, but if not picked up after a while, the trap decays and the pray escapes (so no trapping animals that can fight back, so no bear traps sorry).
Not sure if more sciency stuff would fit the narative of the game, like Ethanol, Distillation Earthenware, Nitric Acid and so on, but it is up to devs to decide.
Could have new stuff like iron sand which apparently found in the river, so maybe even easier early on metal production.
Scale would be nice addition to the game, smaller scale as curio and larger scale as decoration and maybe perhaps a fuctioning weighing system in the game.