rpn

Hi, I have a question about sending rpn messages to a hardware synth with
midish. The documentation for my synth states that the bend range can be
adjusted with rpn 06. With further digging, I found this more instructional
bit of information on what I need to send:

B0 65 00 Controller/chan 0, RPN coarse (101), Pitch Bend Range
B0 64 00 Controller/chan 0, RPN fine (100), Pitch Bend Range
B0 06 xx Controller/chan 0, Data Entry coarse, +/- xx semitones (from 1 to
12)
(B0 26 04 Controller/chan 0, Data Entry fine), -> Not implemented/needed;
do not send

I've tried a few different combinations of commands in midish, but I'm
clearly doing something wrong as I'm not getting the desired results. The
command sequence that seems the most straight-forward to me for adjusting
the pitch bend range to 12 semitones on a pre-defined output called mysynth
is this one:

co mysynth
oaddev {rpn mysynth 101 0}
oaddev {rpn mysynth 100 0}
oaddev {rpn mysynth 6 12}
i
s

Yet for some reason this doesn't work. What am I doing wrong?
Thanks
-zack