Agree that the "missing Matsuri" arc is fine. Remember how much of the series we have to go--it's finished at 13 volumes, and (despite the Dynasty listing) we're 6 chapters into Vol. 10.
It's still a sloooow burn, relatively speaking, but there's been amazing amount of emotional progress all around (although mostly for Miss Sunflower, of course). If the recent rate were to keep up, the last chapters would be about the grown-up Matsuri/Sunflower science babies sitting around reminiscing about their dear departed two moms.