If you want an invisible blend of the fiberglass to the fiberglass to the upper fwd skin once the airplane is painted you need to intentionally sand the entire perimeter so that it exposes the metal along the edge of the tape.
This is described in the video series.
This needs to be done at the aft ends also.
Once sanded, spray with some filler primer and do some final sanding, and the transition can be invisible.
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Van's Aircraft Engineering Prototype Shop
RV-6A (aka "Junkyard Special ")