Here's a photo of a main boom roller reefing setup a friend of mine has on his boat. I've sailed with him for several thousand miles and we used this setup on a regular basis. In the photo you can see he has a roller at the front of the boom that is connected via cable led down to the deck and back to a cable winch to the right of the companionway. The main halyard is led down to the deck and then to a winch to the left of the companionway.
The lazyjacks come down around the boom and attach to a strong bungy cord running under the boom fore and aft and fastened to the mast under the boom and then to a metal tang on the back of the boom that allows the boom to rotate with out wrapping the lazyjacks around the boom. He has a topinglift.
We've not experienced the poor sail shape issue mentioned above with this implementation.
I've been aboard when we reefed down in 30+ knot winds, in the dark, in large seas and was sure glad the reefing worked so well!
On Whampoa, I have a roller furling boom with the old Merriman roller furling gear but I use a slab reefing setup instead as the Merriman gear is slow to reef.
In my case I have reefing lines for each reef point lead down from the leech on the main to a padeye on the stbd side of the boom and then through the sail and down to a cheek block on the port side of the boom then forward to cleats on the port side of the boom. The cheek blocks are positioned to draw the sail aft as the reef is put in.
I am in the process of sorting out what I need to run the halyards for the main and staysail and reefing lines back to the cockpit but for now I have to go forward to the mast to raise and reef the mainsail.
When I singlehand Whampoa the autopilot is my friend
while raising and lowering the sails.
Good luck with your project.