Transform method use steps (distance between points) depending from points count / start / stop / velocity
Example on H4 401 points, start 1M stop 1.5G step = 54,7mm
So you can`t get result between points
Cable->Measure use phase change point (180 degree rotation) so more close to real results, but also can give small errors depend from vrong velocity factor and small points in measure point (use big range)
Most good results method give if you select stop freq little bigger then smith rotate on 180 degree (as on screenshot)
Also need use correct velocity factor for cable
