The information we have on the angle comes from an online session (webinar, I believe) with the engineer who grudgingly stated that yes, the seats did pass testing at 30 degrees. But they like it at 45. And never told us why. Their newer seats (such as the Pria and Apt and Alpha Elite 65) have dual angle lines. I had heard all of their 2012 seats would get the new lines, but haven't seen them on a bunch of seats yet. And that in the US their seats are structurally exact to the 2011 line, just the new lines on the side. So between all of that, I'm pretty comfortable telling parents that going more upright is an option they may choose.
As for the height, the same seat has had a 32" limit (Canada), a 36" limit (US 35 pound rear facing version) and 40" limit (40 pound rear facing version). Now there may be a slight difference in how the 35RF and 40RF seats are made, but still, they seem to have rather arbitrary numbers. The 32" in Canada went away. Also, manuals such as the Complete Air mention 40" or head even with the top of the shell. Many techs would say to do whichever comes first. The Keyfit manual says 30" or 1" of shell above the head, but most techs are fine going straight to 1" no matter what it says. So I'm fine going with the 1" or head even with the shell, since apparently that's been tested in that seat and it works. Overall height is hard since a 36" child may have a 16" torso, or they may have a 12" torso. And that affects how high their head is. So to me, the more important number in a height restriction is not the overall height, but the 1" or head even with the shell.
Wendy