I can play the broken record all day, but I think, eventually, it will get on everyone's nerves. You did not answer the question in the least:
What features in 5.5 or 5.6 are going to make CI 4 so much better than it would be if it targets 5.4?
I think it's a fairly difficult question to answer from the point of view of a framework developer, otherwise I wouldn't bother to ask. I don't think many people have a hard time justifying the use of 5.3, and I think that while 5.4 is significantly more difficult to justify as a necessity than 5.3, it's much easier to justify than 5.5 or 5.6.
