F.8833 is only a disclosure for substantiating the treaty position your client takes on the return.  Nothing from that form is supposed to flow to any line on the return.

Line 1c is where the exempt amount should be reported and that comes from Sch OI, Item L.

Since the SMLLC is a DRE, your client should still file a F.1040NR.

The answer you need is right there in Article 5.