How about "small" technologies that can slightly help your villagers.These technologies is not needed to complete the game.

More small technologies become unlocked as you finsh some puzzles.

Like the "normal" technologies, you need Tech Points to buy them, but the price of small technologies is cheaper (Maybe 1000 to 5000 points?)

Here some idea on how technologies can help your villagers.

Decrease time to catch fish by few seconds (Villager dive less often before they catch the fish)

Increase food points earned for collecting mushrooms. (Mushroom now worth 5 points more food)

Increase tech points earned for collecting collection. (The common collection now worth 10 more points)