Just saw your collection. Technically all mods from Rubble, Dawed, Fungtommy, Revolt and me are guaranteed working. :)

But yes, the game has kind of a limit depending on your available hardware performance, specially VRAM.
Mods getting loaded into the VRAM and use quiet a lot of space there (bigger than the mod itself actually is). So when VRAM got full, no more contracts are getting laoded.