I would make several blanks and get a brand new bit.
I think you'll want a bit with a point so you can vary the width by slightly tilting the base.
When I would watch the guys at the fair freehand the signs I spoke of, having run a router I was utterly amazed. Like I say, they had a half dozens signs with different fonts and you could pick your font. So they knew these fonts by heart and I guess muscle memory. The last time I saw these at a fair was long before CNC was even remotely available in a home shop and they, at that time, could have easily out-run what our CNC could ever produce at this very moment. Now Im sure there were variations in size and accuracy but as far as churning out signs, I couldnt keep up with the CNC even if we populated the entire table with sign blanks in a fixture.
My suggestion would be of course sharp bit, and keep the base of your router waxed very well. That way the base will glide along the work effortlessly. We wax all our tools and it makes a huge difference. Beyond that Id say you'd better have a good sense of spacial awareness, penmanship, and several scraps. Staring at the cutter trying to follow a pencil line I dont think will work out too well.
Post your results.
And there you have it:
https://youtu.be/SV8RFKwXuMc