I strongly encourage people to not ask to be removed, as you won't be able to participate in the blog until it is converted. Since Blogger isn't offering the new Blogger to team blogs for the near future, that could be quite some time from now.
I'm unsure as to why people cannot convert while a member of this blog, since Blogger says it shouldn't be a problem; I suspect it's an unaticipated glitch that hasn't been corrected yet. The support desk is backlogged due to problems associated with the new format, so I don't expect to hear from them anytime soon.
EDIT: If you would like to rejoin the knit-along after you convert, please send another invitation request after you've completed the switch.