I agree with you re mast position weight. I`m 102k and find in nearly every case board planes earlier with mast at front of track.
On question of early planing and early acceleration I have found exactly same.
Mates invariably plane off; accelerate to a good speed and initially leave me behind. As leg becomes longer I normally overall them.
I`ve studied trak logs for past 3 years and invariably compared to two sailing buddies (one at 75 k other at 85) I post lowest moving average but highest top speed.
I`ve messed about with sail sizes ; boards and technique but it still seems to hold true.
Perhaps we are trying to rewrite physics books.Heavier sailor is always going to have lower power to weight ratio but better power to drag .Hence ; slower acceleration but higher top speed.
If I rig up to match mates initially I soon get overpowered.(And then v max suffers; control problems)
Think its a case of accepting our differences. Lighter sailor is always going to pull away inititially ; all things being equal.Play to your strengths.
Lighter sailors will always tell you you can carry a bigger rig you can but only upto a point.
Look at weight of all top speed sailors ! 104 k is perfect.