I would welcome opinions about whether epoxied glass cloth is generally considered necessary to add strength to epoxy-fillets (made with epoxy resin + WEST 405 filleting blend).
My specific question concerns bonding the inside corner of right-angled joints between two pieces of 3/4" marine plywood, where the sheets are already well braced by other joints.
The outside corner of my joints will be covered with glass in epoxy.

Wizbang has said repeatedly that he uses large fillets without additional epoxied glass cloth. From the images of his boats this approach appears to work well even when the
plywood sheets are thin and stressed by substantial bending.