Tangents for remapped UV?

I’ve been using super-scaled tiling normal maps (150x or more), using a mapping node for convenience and because Blender won’t support crazily out-of-bounds UV, and noticed artifacts. I think it’s because I’m remapping the UV coords but not the tangents. Testing supports that theory (no noticeable artifacts from 1-to-1 normal maps on models with max OOB UV.)

Is there some way to remap tangents for Cycles normal map nodes? If there is, what’s the appropriate math? (Kind of confused by the mapping node’s distinction between texture/vector/point etc.)

I’m not seeing the same artifacts when using bump map nodes. These must need UV tangents too. Do these do some magical determination for tangent that normal maps don’t?