Lets be honest here, how much can you really compensate for a longer fork? Manufacturers end up needing to steepen the seat tube angle in order to make up for it. The entire geometry of the bike ends up changing somewhat in order to compensate. The head tube is typically left alone because the slacker angle can help with stability and the increased fork trail will make up for that anyways. Maybe the bottombracket is lower slightly since the longer fork can raise that up a bit. This sort of altered geometry can work well on singletrack, but its not ideal for most types of riding.