Went to my local Hockey Monkey to try on the Cat9 skates. Since I wasn’t planning on buying them I didn’t have them baked, but tried on a size 8R (same size as my TF9) and they fit the same. Toes pressed pretty hard against the toe cap which would fit perfect after a bake. An 8.5 was a closer fit, but after baking they’d open up way too much. Prior to making the switch to True last year I wore multiple Bauer skates over the last decade, all in size 8.5D.
So I’d say the Catalyst line fit the same as the TF line, which would be 1/2 size DOWN from Bauer/CCM sizing