Had to add some oil at the 3rd fill up (~1/2 quart) ... but it's much mo betta than before.
EDIT:
This is good enough for me to decide that the crossover tube is worth the effort (sorta). I'll probably not put it on the Amigo just yet ... but since the valve covers are still not installed on Boy's Ebony, I'll definitely install the port on the right bank before I put them back on.