For me the only weird test is one from which you don't learn anything. Doesn't sound like you're headed in that direction.
One other option you might try with Rodinal and fast film is Rodinal + sodium ascorbate (form of Vitamin C) suggested here:
http://unblinkingeye.com/Articles/Rodinal/rodinal.html and discussed multiple places on APUG. The addition of sodium ascorbate does change the grain characteristics of the film, finer than only Rodinal, and times change so that at 1:50 dilution you should use times for 1:25, and 1:50 times for the 1:100 dilution.
I'll second the move to heed any rodinal (or other) advice from df cardwell here on APUG. A search will bring up lots of info.
Have fun!
Lee