I cut my RV4 front stick for the O-1A Birddog stick grip
to fit in my my hand with my arm resting on my leg. This gave me plenty of clearance under the panel. When I built it back it the late 1980’s most RV4 builders set the stick length similarly. I used the same logic on my HR2 front stick.
BTW, I left my center area clear of clutter or any avionics and hinged my battery box cover. This allows use as a forward baggage area. My odyssey battery is on the firewall.