A very old topic, but interesting so I put some live on this =)
I too have Orbital and have did C-41 without problems. But C-41 developing time is so short.
I am wondering... Orbital is designed for RA-4 process and the manual comes with a calculator which tell how warm (hot!) should developer be when taking account to the air temperature.
So idea is to put warm developer and during process it cools down. Perhaps belowe normal processing temperature.
If that kind of approach works with RA-4 - and I think that I've read something similar about C-41, then how about E-6?
Could even orbital give good result if first developer is a bit warmer than normally (around 40 degree celsius) and in the end of the process, it's one or two degree belowe normal 38 degree?
If developer cools down somewhat linearly, then it averages to 38 degree celsius.