I think you should end up A-OK. I did a Roggenbier recipe with similar traits that people went crazy over. I think I would sub out the chocolate malt for something that is debittered like Carafa Special or Debittered Black Malt. I am not sure how much roasted flavor of the chocolate would come through in 1 oz, but if anything comes through at all - it might make it out of style, if that matters to you.
If you care to see it, my recipe was:
50% Rye
31% Munich
12% Wheat
7% Crystal 120
Hallertau at 90 minutes
Hallertau at 5 minutes
I did a beta glucan rest (110F) for 20 minutes before bringing the mash temp up to my usual mash temp. I would suggest throwing rice hulls into the mash, too. Even with them in there, the sparge was slowwwwwwww.