It because ProSeries only allows 1 of the state SMLLC returns per client (ridiculous I know).  The only reason to mark the SMLLC box on Sch C is to make it carry the info over to the state SMLLC return (I'm i CA, so its the 568).

I dont think you'll be able to Efile 2 different state SMLLC returns, you'll end up with a duplicate SSN error in the EFCenter, so what Ive done, it mark one Sch C as the SMLLC, then I go over to the CA state 568 and complete it and print it out for filing and print the client letter that it generates.

Now delete that 568, and uncheck the SMLLC box on that first Sch C and check the LLC box on the second Sch C and either print that state SMLLC return out and mail it too, or keep it as is and Efile it.

Its clunky, but it can work.

If you have numerous clients with multiple SMLLCs you may want to look for software that can handle this situation better.