I only realised this thinking back a few days after.
What performance effect would it have? Not as powerful, flatter?
My 7m - 6.2m ODs run on RDMs but my Machs are still SDM.
I changed down and forgot and rigged the sdm cams on the rdm. The wind had died and I was really tired so I only got 2 underpowered runs. It rotated OK on the beach but was a bit underwhelming on the water..I only use the 5.5 Mach a few times a year and at the time I put the crappy feel down to lack of wind.

In theory, just means the luff is a bit loose at the mast. The cams aren't pushing the sail out to it's full draft.
Well powered up may not make much difference as wind pressure will push the sail out.
In light winds there'll be a little less power, and during the transition the power may move a bit.
In practice, who knows?

Not that I intend to deliberately rig like that.. I know rdm cams on an sdm don't work..
I suppose mistakes are how you learn..

I have the identical setup as you sail-wise, but I only use RDM. I had to wait for RDM cams, the Mach2 rotated nicely but was "clicky". When I fitted the RDM cams the rotation was more difficult improving when I took out a spacer.

I have to say the 5.5 Mach2 doesn't have anything like the grunt of the 6.2 OD, but maybe I should just be using it when its over 30 knots.

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remery said..
I have the identical setup as you sail-wise, but I only use RDM. I had to wait for RDM cams, the Mach2 rotated nicely but was "clicky". When I fitted the RDM cams the rotation was more difficult improving when I took out a spacer.

I have to say the 5.5 Mach2 doesn't have anything like the grunt of the 6.2 OD, but maybe I should just be using it when its over 30 knots.

I prefer the feedback of the ODs. The Machs feel a bit dead but I don't sail them much.
I changed my ODs to rdm and that made a big difference.For me as a lightweight they feel and rotate better.
I don't use the 5.5 or 5m much so I didn't want the expense of new cams.

Rigged 2 or 3 times my Mach1 5.5 with SDM before i noticed i should have been a RDM.... sailed like a block of concrete, after this 'learning' experience much better with a 4.00 Severne 100% RDM and some additional downhaul ( +1 ) , never had the opportunity to sail it in real flat water, my home spot gets a bit choppy when i need a 5.5 ....