The evidence: hold the treatment fixed, vary only content

Each arm adds the same number of pairs to the same base and trains the same matcher, three seeds. Arms differ only in where the added pairs came from.

13 training sets spanning semantic keypoint, optical flow, driving, and point-tracking data · scored on geometric (6 flow/tracking families) and semantic (4 keypoint benchmarks) accuracy at PCK@3% · matcher CATs++, replicated on GLU-Net.