Hi Ethan,
I just updated a thread regarding creating a text-mode matrix report. In this example, it is an Assignment report and I was able to group the matrix report on the vertical axis based on two custom Task fields.
https://community.workfront.com/p/fo/st/topic=62&post=4416#p4416
Which type of report and field are you having trouble reporting with? We can't easily solve the Chart issue, but I would think there is a good chance it could at least work for the Details/Matrix tabs.
To resolve the Chart issue, there is a complicated way to do it in most cases, using calculated fields. I did this recently and there is a long thread explaining how to do it at:
https://community.workfront.com/p/fo/st/topic=62&post=4036#p4036
In both cases, Doug Den Hoed (AtAppStore guru) provided the solution but he made me work a little bit to find out how to implement it :)
Regards, David.