Rockstar should have included something like this in Definitive Edition, like in GTA Online.
Call for an airstrike when you want.

How to install:
Cleo Redux must be installed!
Put astrike.js (and nuclear.js if you want) in your Cleo folder (\Rockstar Games\GTA San Andreas - Definitive Edition\Gameface\Binaries\Win64\CLEO).
Also, extract astrike.fxt in you cleo_text folder.

How to use:
Type "AIRSTRIKE" to call for an airstrike. It won't work in interiors/Liberty City.
Move around with WASD (control movements) and your mouse. Press SHIFT to move faster.
Press Up and Down arrow to select radius.
Press T (exit widget) to exit.

Known issues:
-Due to the game limitations (even in Definitive Edition), explosions won't be spawned at once.

Author: starblind94

BONUS: extra file named nuclear.js is included. It works the same way like air strike does but it spawns a lot of invisible Vortexs and it creates a single explosion at the center. Just type "NUCLEAR" to test it. The final explosion will be huge, be careful!