I’ve made logos that way. Lay my “word” and the outter shape of the logo out in masking tape, laminate a panel of resin tinted fiberglass over it and cut the letters out after it set up. I’ve also laid veneer panels out and glassed over that, and I’ve laid hemp panels out and glassed over those.
I’ve done it but I have no idea what type of craft & conditions you are working with that would be so hyper sensitive to resulting flex issues, clearly no ordinary surfboards or wave conditions, I have no comment on that.
If i did say a yellow tint on 2oz glass about 100mm wide at 100mm right side of the stringer, would the blank twist duing the curing phase as only the right hand side of the board will have glass.