hmmmm - if I'm following your correctly, you're thinking of having the door *open* to the inside vs. the outside? If I'm on the right track here, I'll explain why that's not as desirable:
If you are doing deep litter, the litter will need to be more shallow than the door or you'll be moving litter each time you open/close the door. Also, depending on where you put it, you'll have to walk inside the coop each morning/evening to do opening/closing duties. For some that's no big deal, for other's it's not so desirable. I don't know about other BYCers chickens, by my girls head bump the door when I'm unlocking it in the morning. They are always VERY anxious to get outside to the yard. Goof balls. If I opened the pop door to the inside, then I'd be pushing chickens out of the way constantly just to be able to get the door opened and latched.
Remember, if you're going to do deep litter, you'll want to cut your pop door around 9 inches above the floor level. That way, each time you open the door, shavings won't spill out. I'm guessing that if the door is this high, it wouldn't really matter if you wanted it to open to the inside or to the outside. Personal preference I guess.
Somebody please correct me if I'm wrong here....