That's what they've done in the past, when they've changed their design midstream.
RRS will have to redesign their foot, however what's even more strange is that the Canon stock foot won't balance either under the same circumstances.
Good to know, thanks, Rich!
I agree it's really odd that Canon didn't design the foot to balance their own lens properly. I suppose if necessary, one could use the RRS long lens support package, where the 10" camera bar would allow a longer traverse for balance.
John, you may just want to return the foot since it hasn't been used yet and I'm sure RRS will just re-sell it as a 400II foot.
I'm going to give it a try first. As I stated above, I don't think it'll be an issue with the 600 II, since it's 2.5" longer, has a larger front element and heavier hood compared to the 500 II, meaning it should be relatively more front-heavy, shifting the CG forward.
Please remind me, Rich - IIRC, you are talking about the 500 II running out of room on the clamp, with a 1D X and TC attached, correct?