I recently converted my TT bike to tubeless, for use in triathlons after having running tubeless on my gravel bike (which I ride ~90% on pavement) and mountain bike over the past 2 years. It's been great with zero downsides on all 3 bikes. In a race this past weekend on my TT bike, I lost ~2-3 psi between when I pumped the tires up in transition (~90 psi) before the race and after I collected the bike after the race (around 5-6 hrs later). Super minimal and well worth it for me. I'll never go back.