Hi there,
3.5 hours after take off for dinner is too long. That only leaves 5 hours (approx.) to sleep. On US West Coast UK bound in F you would expect to eat in 1.5 hours and then get a decent nights sleep.
It is great that the crew are enthusiastic but it may be the experience that is the issue here. If they are fairly new and young they may not have the correct perception about what most of us in F want. If it is a day flight then yes some may want a nice, long slow meal but generally if it is overnight it is eat at the start as fast as you can (but without feeling rushed) and then sleep until either the second meal at about 1 hour before landing or no meal at all. If the flight is US East Coast to London many will not do anything at all but sleep the whole way.
With a bit of training and experience this can easily be sorted though....
FD.