As for getting tech points from collectibles you already own, if you're quick enough there's a little trick I did to start mine off.

Click to reveal..

When a collectible pops up, pause the game and drag a child onto the collectible. If you have more children in the tribe, quickly unpause and pause the game again, and drag another child onto the collectible.

I've been able to get tech points from up to 3 children at a time. You just need to make sure you're quick with the pausing.


Good luck!
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