Hey David!
I am using ProRes, the Y-Axis is 0 and I tried 2 fonts but not much more. It is very odd though. It looks fine in the Boris dialogue box but then when I superimpose it into the timeline it gets larger than it was in the preview window. I suspect there is some sort of scaling going on. I reset the properties for the title too.
Also, in my screenshot, the “extreme” is the only one I notice jaggies on. The lower “overshoot” does not appear jagged (to my eyes).
I will try to play with some other fonts and the blur you mentioned.
Thanks for your feedback