QBI for the K-1 should be reduced by §179 on the individual return for the reason you mentioned.  Think this is not working as it should, at least for 1120S, across all of Intuit's ProConnect tax products.  The fix for Lacerte/PTO is scheduled to be released later this week but not sure about PS.

FWIW, QBI is working properly for Sch C and 1065 K-1 with §179 on Lacerte/PTO.