Last time I rode in the TT was 2000, only got in 9 laps of practice, then the race was shortened to just two laps due to bad weather.
Seemed an expensive two weeks for just 11 laps.
Thankfully for me I only had one bike in one race that year, those with 3 or 4 bikes really had trouble! (I had four bikes in 96 myself, couldn't have managed without morning practice.)
Early mornings were tough going, for riders, pit crew and ofcourse marshals and volunteers.
But it is valuable track/bike time.