Entirely depends on whether you're concentrating on beating the clock, or your position relative to other racers (eg. when riding in a group). Once you've got a feel for the track - where best to take the bend, which bit of that single bump is least likely to induce a scary wobble at 30mph, when to change gear, or how much extra beans you can give it on the climb, etc. time trials are indeed boring, and best kept to a lap or two[1]. Half the problem is that you don't have enough brain capacity left for arithmetic at race speed, so it's hard to work out whether you're actually doing well or not.
Staying in a group or overtaking requires concentration. More so than with upwrongs because even unfaired recumbents have a lot of feet and chainset blocking the view immediately to the front, and because the cornering dynamics of the different types of machine (especially bikes vs multitrack) can be quite different. Particularly important is not getting your pedals tangled in the wheels of upright trikes. Plus, unless you're at the top end of your group, you've got to be on the lookout for faster machines appearing from behind and aiming for that gap you wanted to use.
But, TBH, for me the sheer novelty value of being able to spool the Baron up to full speed in the corners without fear of pothole-related DETH is a strong motivating factor.
[1] I went back on Saturday evening and had another crack at the single lap of the lower loop on my Brompton. Annoyingly, according to Strava, I was 8 seconds faster, though I suspect this is as much to do with favourable wind and not having stood around in the sun for half an hour as it is about acceleration.
