Transmission oil change and a Shudder Issue

I read in this forum that the transmission holds 10 quarts of Honda ATF-DW1 fluid but the drain and refill procedure replaces only 3 quarts of old fluid with new fluid. What remains is 66.7% old fluid. Several of you run the vehicle until the transmission fluid warms up or drive the vehicle for a short time and repeat the drain and replace 3 quarts of fluid. Now what remains is about 44.5% old fluid. I guess Honda believes the 66.7 procedure is sufficient to keep the transmission functioning appropriately.
I have been performing the 66.7% procedure and my transmission began to "shudder" when shifting between 2nd and 3rd. A transmission repair shop recommended adding 4 oz of Lube Guard Instant Shudder Fix and that cured the problem. I now am at 100,000 miles and plan to perform the 44.5% procedure (or two sequential changes) and see if the shudder problem reoccurs.
Any others of you have experienced the shudder issue? If so what was the solution?