Hi Chris:

Michael showed right where are problem areas :)
I suggest a little modification mantaining main shape



Select text's curves,copy and move



turn on points,delete that little line and move vertex



in case of -4- you'll have two triangles



now you'll able to fillet to 1,5 mm



file attached: M

Ecellent trick!

Sorry what is the meaning of "4-i","4-e" ? (Internal / external ? )

Yes...it's for indetify outern triangle and inner triangle,about -4- on third image,it's a close up and could be not clear which area i'm showing
4-i = 4 inner (interno)
4-e= 4 outern (esterno)

forgive me i did it quickly...i mix Italian and English..some tolerance.. :)

Many times i found same problems when filleting solid fonts,so i decided to show this "shortcut": simplify or use rebuild command to clean points of font splines before extrude.

M

THx for the info! :)