There are actually potential technical weaknesses everywhere in Carlos's game. The fact that he's been able to overcome them so far is a testament to his extraordinary athleticism, mentality and talent. Nevertheless, I think unless he can adjust his technique he will always be a player with high peaks but limited consistency.
Forehand:
Everything about Carlos's forehand is geared towards generating explosive power. His forehand takeback is high and uses an inverted "next-gen" racquet head, creating more space for acceleration. Rather than dropping the racquet into the traditional spot behind the back hip and only then firing his hips, he uncoils into the ball with his arm still held relatively high, maximising the rotational acceleration. Even the straight hitting arm adds potential power.
However, optimising the shot for power comes at the cost of quick reactions and control. Carlos's technique cannot be easily abbreviated to react to an incoming low, hard and/or deep ball. When he doesn't have time to set up his legs (especially when on the run), his reliance on core rotation to generate power can be exposed. The technique also makes his natural FH return of serve relatively inconsistent.
Overall, his forehand is a fantastic attacking shot when confident, but quite limited in terms of defence and rally tolerance.
Backhand:
Carlos's backhand uses a very low takeback without much loop. He is still able to generate a lot of pace by muscling it, but he doesn't produce a lot of topspin. We've seen that this backhand can be an extremely effective weapon when he steps into the court, takes the ball early and crushes it crosscourt.
However, it has a lot of limitations. It's risky to hit down the line with so little topspin. The lack of margin can make it an inconsistent shot. He also has to use relatively high effort to generate his power, making it difficult to out-grind opponents from deep in the backhand corner. Because of these factors, opponents with elite backhands who can hit hard and deep crosscourt can really cause problems for him - examples including Zverev, Medvedev, Sinner and so on.
Serve:
Carlos again gets a lot of power on his serve thanks to a pinpoint stance and fantastic leg drive. However, I dislike everything else about this shot. He tosses the ball straight up in front, which makes it hard to disguise where he's aiming. He doesn't coil his body much, which would add a little extra power and disguise. Finally, the backswing is stiff and his right elbow is moving back into the correct throwing position (behind him) until the very last moment.
FAA's serve is somewhat similar to Carlos's, but far superior (granted, he's significantly taller). That could make a nice model for Carlos as he looks to improve. He desperately needs to develop a good slice serve on the deuce court.