Shears will certainly work well. The HF one has come up a number of times on this forum, but there seems to be a lack of real user experience with it. I tried a Boston 2612 (steel insert blade on plastic support) paper cutter with 1/16" boards, but the blade dulled very quickly. An older cutter with the cast/forged steel(?) blade might work better.
As you know, FR4 is very abrasive to the blades. One shop I was with would not allow FR4 to be cut on any of its good shears -- those were heavy duty industrial, not hobby shears.
Cutting boards remains my least liked part of any project. I cut the board to rough shape with whatever saw blade I am tired of using, then use a belt/disk sander to final dimension. John