I have similar body dimensions as OP - 178/89cm. Being middle aged and not super fit or flexible, I need a reltive high stack and short reach to feel comfortable with 6-8cm saddle to handlebar drop on my (gravel) bike.
In my limited experience, moving the saddle forward to reduce reach may not help much with reducing load on hands. For me it has been better to reduce reach with a slightly shorter stem (90mm) and a handlebar with less reach. I am using a Syncros Creston 1.0 X with 60mm reach and 115mm drop.
also the shifters can reduce the reach (on hoods). I believe GRX Di2 shifters have slightly less reach than non-Di2 versions.