Blade & Sorcery: Nomad is the recent port of B&S to the Quest 2 platform.  As with most if not all ports of PCVR games, the difference will mostly come down to game fidelity and graphics. B&S: Nomad is optimized and built with the Quest 2 in mind making it the same game in practice but a different game in code. If you wish to mod Blade & Sorcery, you have to make sure you download it from the correct nexus.  Blade & Sorcery mods are found at the B&S Nexus.  Meanwhile, Blade & Sorcery: Nomad mods are found on the B&S: Nomad Nexus.