version 1.0.350.1 (patch 1.36) , finding the "best" gameconfig is about balancing stability with the number of add-on mods you want to run. Because this is an older "Legacy" version of the game, modern gameconfigs won't work, so you need a version-specific file to prevent crashes during the loading screen or when adding custom vehicles.
While “103501 best” remains legendary, newer gameconfigs have emerged for post-Cayo Perico patches (builds 2545, 2699, 2802, etc.): gta 5 gameconfig 103501 best
Low FPS: If you chose a "5x Traffic/Peds" version, your CPU might be struggling. Revert to the "Stock Traffic" or "1.5x" version. version 1
The "best" modified configuration typically applies a multiplier logic. version 1.0.350.1 (patch 1.36)