Is there a better way to do this? My method is unusably slow. I have played with several options (making assumptions about words separated by space having same font info, etc), but I haven't really found anything I'm happy with.

Defer FP updates method. You are updating the text properties character by character. dump them all into the transfer buffer and update them all at once.

LabVIEW

Preserving font properties after concatenate string and updating control

Solved!

@BowenM wrote:

I ended up going with a combination of defer updates and storing the font properties in a shift register to make it quick enough. I didn't realize defer updates would make THAT much of a difference... thank you.

Defer FP updates does make THAT much difference in the scheduling for the UI Thread you should remeber that. also , run VIA and make sure that there are no overlapping controls.... it takes twice as much time to redraw FP Objects that overlap.