[suggestion] Give a story reason for why we can't enter locales that require a tech
Maybe you were planning on doing this already, but I'm not sure. I think it's important to tell a player entering a witch's hut or ruin why nothing is happening. For example, let's say I walk over an ancient ruin. Instead of blankly staring at it and scratching my head, I should get a pop-up that says "You walk up to an ancient ruin. The entrance is shut with an advanced lock that you dare not attempt to fiddle with lest you be killed by a trap. Maybe you should ask your scholars to take a look at it before you return.... [Requires Ruin Delving Tech]"
Something like that. I'm sure you can do better, but you get the idea.
Thanks!