It should work. As I understand it, the CMS and CS 70 Precisio (that the wheelset is for) share the same "narrow" dimension. However, they don't share the same "wide" dimension (hence the need for two distinct lengths of rip fence/stopper; one for the CS 70 - which fits the MFT/3 BTW - and the other for the CS 50 and CMS).
That said, a member with keen eyes spotted a modified set installed on an MFT/3 at the Festool factory here:
http://festoolownersgroup.com/festool-tools-accessories/festool-visit/msg427134/#msg427134
This would imply that the set is (maybe?) too long for the narrower dimension CMS (and, therefore, contradicts my understanding on the shared commonalities between the CMS/CS 50 and the CS 70) . If so, that could be remedied with a hacksaw, I would think. Or, simply, that a longer piece of tubing (which the folks at the factory would have access to) was used.
Either way, I'm personally waiting for the wheels that appear on the new versions of the CS 50 and new CS 70 to show up on EKAT so I can buy a couple sets and install them on my CMS and MFT. Much better solution, I think, and should be more reasonable in terms of price too.
Alternatively, if the price is off the charts I'll just use them as the inspiration for a shop-built set. If I go with the OEM set then I might also, at the same time, order the improved cord wrap (which features integral storage for the mitre fence).