Winning the Leagues Cup gets them into the CONCACAF Champions Cup next year with a bye, and finishing second or third (or winning the US Open Cup) gets them into the First Round of that tournament. There's also talk of having CONCACAF teams in the Copa Libertadores.
Given how far back they are in the League, maybe they should just prioritize the other two tournaments?
MLS is shut down until after the Leaguea Cup so they dont have to de-prioritize MLS. I still doubt very much that Messi plays at Cincy in the US Open Cup. My guess is they go all out and try to go something like 8-2-2 to make the MLS playoffs because if they made it, they'd likely win it.
Also, I hope Miami finishes Top 3 in Leagues Cup and then win the CCL next year because that gets them a bid to the 32 team summer 2025 Club World Cup in the US. Similarly, I hope Al-Nassr win Asia. Can you imagine a group of Miami, Al-Nassr, and 2 Euro giants?