Thanks for the response. What I recalled reading was that the actual chemistry of the two films had a detrimental effect on each other when in a communal bath. I'm happy to hear it is not so.
I don't intend on doing this often but having just acquired another Jobo I want to soup the two leftover 220 rolls from when I stopped 2-3 years ago and see what's on them. I like surprises After this it will be almost exclusively Fuji for E-6.