No. The highly compressed rips strip out the Ad-hoc wireless files to save space. You need a full 1.5GB ISO for LAN multiplayer.
Use an app like ZArchiver to extract the ISO from its ZIP or RAR container.
Legal gray area but safe. Search for "GTA San Andreas PSP Remaster" – multiple community uploads exist here.
While many online sources claim to offer a "highly compressed ISO" for Grand Theft Auto: San Andreas on the PPSSPP emulator , it is important to clarify that GTA: San Andreas
Rockstar Games never produced a PSP version of San Andreas due to the original handheld console's storage and hardware limitations.