Hi Matt,
I would be interested in some more information regarding your specific settings, e.g. Rodinal dilution, developing tank, etc.
I am currently "working" with a similar setting
Hassi 500CM, 150mm T CF
Gossen Profisix exposure meter
Rodinal(Adonal) 1+50
Jobo 2236 developing tank with 700 ml liquids, resulting in 14 ml developer concentrate
Agitation: 5x in the first 30 seconds, once every 60 seconds thereafter

My first preliminary test results look a little bit different
80 ASA
18C (64.4 F)
10 mins

Looking forward reading from you.
Kind regards from Cologne