Hmm, I'm not exactly sure what to make of it, TBH. I don't think the EW is because of the EBT, it doesn't seem that he's getting too much daytime sleep. Maybe it's because he uses the EBT as a CN and then doesn't settle for so long.
Do you think part of the trouble settling for EBT and possibly the EW is because he lacks IS skills? It seems like the routine is a good one and works to have the long last A as you said he doesn't really get fussy til 6:30, which is about 4hr. Maybe it's worth trying to get him into the crib over the next week or so.

What do you think?
Will be interesting to see what happens tomorrow morning (or I guess it's probably morning for you now!), as you had a 'normal' BT last night...