Homeschool HS Geometry - can Khan be used as a stand alone?

Hi! Last year my home schooled son started using Algebra by AOPS. He ran into issues and we started using Khan to "supplement". I compared the topics of the Algebra in Khan to those in our text book and found that other than order of topics, the material covered was similar. My son really enjoyed the Khan format and the positive reinforcement. He worked problems until he received 100% on nearly every exercise therefore getting a lot of practice.
I am looking to use Khan geometry this year. The reviews I am seeing overwhelming say that Khan should not be used as a stand alone program. I am struggling with this since I feel that the Khan Algebra was well done and that he learned everything he needed to (once I figured out that I still needed to be with him to keep him focused on the lessons learned as well as teaching how to take notes and use those notes to study/review).
My issue comes in that after "mapping" out what I expect the year to look like, I found that the Khan HS Geometry would take about 80 days. My estimate may be slightly off, but I don't think it is off by 100 days but I guess it could be. I am trying to figure out if there are other "topics" that I should include to fill out our year. Or if I should be getting problems from another curriculum to supplement (most reviews say that Khan should not be used as a stand alone because there are not enough practice problems -- I do get confused because it says that there isn't a testing of the skills, but in both algebra and geometry there are regular quizzes and tests).
I appreciate any guidance you can offer.