Not as far as I can see. I did however find a hint that seems to be able to remap the numpad keys automatically but I haven’t tried it. This seems to be exactly what you asked for originally.
SDL_HINT_KEYCODE_OPTIONS
“hide_numpad”: The numpad keysyms will be translated into their non-numpad versions based on the current NumLock state. For example, SDLK_KP_4 would become SDLK_4 if SDL_KMOD_NUM is set in the event modifiers, and SDLK_LEFT if it is unset.