He's just trolling at this point. Has to be. No one can be this stupid
How this works:
1. Trump says something he'd like to be true. "Nobody has done more for Puerto Rico than me."
2. We all say it's outlandish. Meanwhile, while we react, his army of bootlickers pore through his presidency and finds a tiny factoid of evidence that, when mixed together with some extremely flimsy reasoning, suggests that Trump has done something for Puerto Ricans. It can be any act, no matter how small, and the logic doesn't have to be sound. In fact, it's better if the logic isn't sound, and that the benefit isn't great, which I'll get to in a second.
3. His base laps up the rationalization and, consequently, what Trump would like to be true now is true among those who have agreed to the shared delusion. Ever wonder why Trumpists keep saying things like "the media never reports on all the good things he does?" This is (I think) what they're talking about.
Now, about that flimsy logic based on minimal evidence. This is actually a feature. The Trumpists have highly compartmentalized minds, and one of those compartments believes that Puerto Ricans are subhuman brown people. They have to square "Trump has done more for the people of Puerto Rico than any other president" with an underlying desire that no president ever do anything for the Puerto Ricans. So if the argument for what Trump has done for them is extremely tenuous, then they walk away affirmed that nobody really gives a shit about Puerto Ricans.
Every little compartment in their tiny little brains gets a dopamine hit from this entire process.
Trump says stupid shit because his vile henchmen and deplorable base are 100% dedicated to distorting our collective reality until it's not stupid anymore.