A year or so ago I bought a digital protractor for doing cabinet trim work and baseboard miter cuts. Then when I started my latest short kit build I found that the protractor was a great tool to accurately measuring both stick and sheet pieces from the plans. Once measured, I just set up my miter saw and made very accurate and square angle cuts. This was particularly useful if you have similar angles on multiple pieces. I found that the parts fit perfectly, making tight gluing joints. The results were that I had an accurate and strong framework with no need to have the glue gap filling under the wood joints.
But wait, there’s more.....I also used it for finding where to position my engine mounting. I knew the angle of right thrust I needed and was able to accurately position the offset mounting hole pattern

required on the firewall.
It was good value too, about $12 on Amazon.