Thanks for the replies.
As to the why?
I get it. However see if you can improve the situation:
Wear rubber gloves
Pin fit gets looser over time with wear
Use a drop cloth in cockpit to avoid dirt
Improve fit/operation pin remove/install with guide tube
Does the pin have a point on it?
Your desire to not deal with cockpit access to remove cowl is reasonable. "Van The Man" is a pretty great aircraft designer and engineer. Sage advice is build it PER THE PLANS.... often the better choice, lighter, less expensive, simpler to build and maintain However owner's, either the original builders or secondary owners tend to want to add their own custom touches.
The main reason to go inside the cabin is a SMOOTH look. Is it worth it? No not for me, but as other stated they would not do it any other way.
Others LOVE using 1/4 turn lock fasters. They add weight, cost and does not have the smooth hidden look. However they work also.
Some have used piano hinges to hold on wing tip fairing. It looks nice. Is it better than blind rivets or screw and nut plate? Beauty is in the eyes of the beholder. I like SS flush screws and nut plates. Although rivets are fine if you don't mind drilling them out in the event you need to remove fairing. In 10 yrs of flying my first RV the wing tip fairings never came off. NAV & Landing lights were accessible from outside. Cowl obviously needs to come off at least every 25 hours.
TWO MAN JOB - I can and have removed and reinstalled my cowl solo 1000 times (99.9%) but having two people makes it easier and more fun. One person is awkward even with cowl pins all from outside cockpit.
It is your plane. If you want to convert it can be done. Up to you. HOWEVER if the pin is hard to get in from cabin side it may still be hard to get in from the Prop side if the hinge is not aligned. No debate pin coming out Fwd towards prop is easier. If your cowl is painted then careful work is needed, yet may still require a touchup and might not be perfect.
In this case FAR's do not prohibit you from making Mod. It does not affect the performance or significant systems (please read the FAR's to see what you can and can't do). EAB plane is not a total blank check to do whatever, even if the original builder. Some Mods require A/C going back into Phase 1.