Looking back on season 2 as a whole in terms of who undermined Milolissa - I don't fault Dan and Swampy, it certainly wasn't them and I don't fault the fans for not pushing hard enough, they tried their best and I applaud my fellow fans' efforts.
No, I blame Buford and Baljeet in 'The Phineas and Ferb Effect'. I feel like if it wasn't for them, Milo and Melissa probably would've hooked up in the show, but instead they turned the tables and forced us to look outside the show's timeline.
However...and there is a however - if the show were to end at 'Sphere And Loathing', I'm putting a call out to my fellow fans, especially the Milolissa shippers - do not give up! Write your own seasons of 'Milo Murphy's Law'! Finish the story! Now is the time to channel Barack Obama and say...YES WE CAN!