Are the 4 new stands online yet ? These will obviously provide scope for further expansion. Presumably the lack of stands is one of the main factors restraining further Jet2 aircraft being based at LBA. I'm sure if Jet2 based additional aircraft at LBA, there are many routes which can be opened up to adequately fill them.
The extra "night stoppers" might cause issues in the terminal given the already heavy passenger congestion in the early morning. Another 4 733's with early morning departures would result in the dep. lounge becoming too overloaded. Something needs to be done pretty sharpish if the growth rate continues.