With UN-54 I used original Agfa Rodinal 1:50, 20C, 13min (2 inversions each minute) but I fell it can be bit shorter next time, 11.5min or so. Highlights look little bit dense but it scanned beautifully on my scanner.
With HC110, I used Dilution H (1:3+1:15) 7min 20C (2 inversions each minute) and this one also can be shorter, next time lets say 6min.
I hope you can figure your starting points from there.
I'm planning to try it with Xtol 1:1 in next few days.
13 minutes is way too long for UN-54 in Rodinal 1+50. Try it at about 8 minutes.