Finished the retention reduction mods. Had to remove the chute assembly to keep the transition area short and allow access to the channel between the burrs and the chute. To keep the indicator light, it was installed to the left of the new chute. I also made a duct piece as part of the stainless panel that eliminates the housing's offset in the original exit channel. It is now a smooth channel from burrs to chute so there is no place to catch grinds. There is a slip fit between the anti-popcorn plunger and the funnel, so when it is moved up and down while grinding, it works as a bellows. After the grinder stops the chute cover is removed to allow getting any grinds left in the exit channel. This is where almost all of the retained grinds are.

I am currently averaging about .1 gram of retained grounds. Misting the beans with two pumps of water improves flow and reduces clumping. This works much better than the OEM setup for my needs.