8829 and mortgage interest limitation

[3pza2]

Client with schedule C has mortgage interest principle of 780k.
When I allocate % of interest in 8829, the remaining flows in schedule A. 
So technically Sch A has correct amount up to 750k, the rest is in 8829,

but overall combined Sch A + 8829 has 780k. 
Is there a 750k excess limitation rule for 8829? Or is it just for schedule A? 

[TaxGuyBill]

Just Schedule A.