@mcmurray, Not sure about the OLED issue, but in regards to the LH/RH behavior, when I built my right handed v4+ I also had seq_l.ngc working properly with the boards plugged in in left hand configuration, with seq_r.ngc behaving strangely when plugged in in right handed configuration. I saw an earlier post by @sis.tm that helped me jump that hurdle where he mentioned:
So, based on that, I then tried the final firmware (at the time. 0.95?) with the HWCFG right hand MBSEQ_HW.V4 with everything plugged in in right hand configuration and everything worked fine. I just chalked it up to the seq_r.ngc file that I had and moved forward.
Once it was running the seq_v4 application, another thing that threw me off a little was my TPD behavior not matching what I had seen in videos and pictures. By changing the setting of the TPD on the Midibox itself by pressing Utility -> options -> opt26 -> "Green LED: POS Red LED: Track", this gave me the TPD behavior I was seeing in the various videos and pictures.
Not trying to derail any troubleshooting you guys have going on here in this thread, but maybe try loading the seq_v4 firmware and use the right hand MBSEQ_HW.V4 config file with it all plugged in in right hand configuration and see what you get.
Just my observations.
Here's the post I referenced earlier: