I like it. I've always made mixes with bonus tracks and b sides placed where they flow best, not always at the end of the album. It's kinda reverse similar to some vinyl releases where certain tracks are cut.
I get the concept, and I can dig it, but it just feels a bit peculiar to me... If the album sounds better with the b-sides in specific spots, then why not then just make the last two/three songs exclusive instead..?