It is possible to register functions with defaults arguments and call them from the script.

Yes, but you need to inform the default parameter value in the registration.

// C++
void func( int a, int b = 1 ) {}
 
// Registration with AngelScript
engine->RegisterGlobalFunction("void func(int, int b = 1)", asFUNCTION(func), asCALL_CDECL);

thnx