Large number of columns in Django

I have performance data for a model execution instance that I am trying to store in Django (sqlite backend). There are 435 timers with 11 different attributes per timer resulting in 4,785 unique values that need to be stored per run. I wrote code that generated the models.py code. It gets 1,564 columns in and throws the below error. There are no duplicate columns of that name as I have checked the models.py file. When I switch that line with the next in the models file (and make a new migration) it dies at the same line number but new column name.

First time through:

django.db.utils.OperationalError: duplicate column name: CAM_export_processes

Second time:

django.db.utils.OperationalError: duplicate column name: CAM_export_threads

What limitation am I hitting here?