Thanks for pointing this out, I believe I see the problem already.
I had used the vanilla surface ruins rarity values as a base and set the most common one to 0.035, the middle tier one to 0.025 and the one you're seeing most frequently to 0.15. This clearly should be 0.015 and is an error on my part. I don't wan to release a whole new version for the sake of a single zero so I'll build a new variant over the weekend and release it with that.
If you wanted to correct it yourself it's very easy to do. You just need to open lorddans-surface-translocators-b1\assets\game\patches\survival-worldgen-structures.json and change
"chance": 0.15,
to
"chance": 0.015,
and save the file.
I found this to be true when making this mod, I was quite surprised at how common they actually are when they appear to be much rarer than they actually are.