Sorry I ruined my boat for you, but I didn't build it for you, I built it for my wife and me and funnily enough we built it for what we wanted.
That is the joy of building a semi custom boat you can have what you want, and this is what we wanted.
I expect for the right buyer my modifications will be valued. The modifications we put in to the boat will be welcomed by another tall boater. because they may want to own a boat where they won't hit their head in the cabin, a boat where they can sleep stretched out in the V berth and not curled in a fetal position.
A tall buyer who wants a boat that accommodates them physically and doesn't want to gunnels that barely reach up halfway up their tib / fib will be interested in my boat.
The center of gravity of a person changes with their height and since humans are top heavy, taller people will have a harder time balancing.
In other words I am more prone to have a more difficult time dealing with the motion of the boat (keeping my balance) while reeling in a fish, cutting bait, or moving around the boat at trolling speeds or slower.
So when you compound the effects of being taller, taller people having more trouble balancing than short people, a shorter person will always be safer than a taller person assuming they have the same level of athletic ability and sense of balance. Add in age to the equation and being tall has risks that increase with age. Shorter people are less likely to fall down, and when they do, they're less likely to be injured. Simply put, shorter people are closer to the ground, which makes falls less dangerous for them.
So when you consider taller people are more likely to fall, and on a boat there is the added risk of falling overboard just by not being able to catch oneself it makes sense for me to want to mitigate that risk by as much as possible by increasing gunnel height by 8"
As far as resale goes , when we sell the boat it would not be a complex project for the new owner to remove the 8" gunnel extension and smooth out the top surface of the original gunnels. Compared to what some folks on here have to do to modify the used boats they buy, that is a pretty simple job.
Regarding boarding and disembarking , there will be a transom door on the boat.
If the gunnel extension ruined the build for you, just wait for the stern seating area .