I would run out this season’s TT events then spend your base dropping a few kg if that’s your goal. You might as well enjoy the events while you can and then schedule out to your first A race next year/season. You could also do a modest calorie deficit without too much impact on performance if you wanted to.
Dont be disheartened if you dont get much FTP increase in speciality… that phase is more about fine tuning what you’ve achieved in base and build.
I don’t think you should be making either/or decisions about power and weight with such short-term timescales.
Do specialty, eat healthily but make sure you fuel your workouts. See how the TTs go, and maybe you’ll drop a tiny bit of weight. At the very least you can start instilling some good eating habits.
But start thinking now what you want to achieve for next season and start putting together a realistic long-term plan for achieving it, so you’re not trying to make this decision this time next year.