When we went, because we knew we could modify we didn’t worry about whether the return time was as late as we wanted. We would just book it and then push it back by an hour or so, whenever we noticed the return time was roughly when we wanted it to be.
That way you keep booking every 2 hours and can modify less than ideal times to be later. It worked a dream when we were out for the day and wanting to do Epcot in the evening. Originally we had rides booked for 11ish onwards. We just pushed them all back until after 7pm.
Very, very occasionally we missed the opportunity to get that ideal time, but usually it worked great.