Hi Andrew,
No, you didn't have to fill in the groove but the JB Qwik has a tendancy to flow a little bit.
What you want to do in cases like that is after the JBQ hardens, sweep the bit through the groove to clear anything that oozed through.
You want to maintain the shape of the groove throughout, also when your doing that you can touch up any spots that may be a little rough or shallow.
Nice job.
Karl Fortner
Tacoma, Wa.
Gadgetman Tacoma