There are available for the Switch version, most of which were released as free content. Sonic X Shadow Generations
Do not mix DLC from different regions. Use the same region as your base game. sonic forces switch nsp update all dlc
Searching for "all DLC" is one thing, but understanding the value of that content is another. Here is a breakdown of what you unlock the moment you install the complete DCNSP (DLC NSP). There are available for the Switch version, most