Summary
Transit tracking of Mars (elevation at transit = 45) was followed by repeated pointings on blazars 1921-293 and 1958-179 (41 & 52, resp.) Mars was tracked using the map16 method.

while the pointings on the two blazars are look like this :

(Note : the vertical scales are different.)
A case could be made that a 2"-3" sharp step is seen in all three datasets at 180 degrees azimuth, but none of the data before and after transit is anything like the simple baselines we expected based on recent data. A repeat is pending.