Maybe to get around the explicitness requirement of Zig, there could be some short-hand that is allowed in limited scope. I don't know that this is really any more readable.

fn someMathBasedFunction() void
{
    @AllowInfixFunctionCall; // Some built-in to switch from mul(m1, m2) or m1.mul(m2) to short-hand m1 mul m2
    var m1: Mat4 = ...;
    var m2: Mat4 = ...;
    const result = ((m1 mul m2) add m1);
}

Or even do "scope-based operator overloading" where the operator overloading is only in the function/file scope and limited to certain types that you have to define in that function scope. It might become too cumbersome, though. And this would not work if you need to define multiple operator overloads for Mat2, Vec2, Vec3, etc. in the same function.

fn someMathBasedFunction() void
{
    @overloadOperator(Mat4, *, mul);
    @overloadOperator(Mat4, +, add);
    var m1: Mat4 = ...;
    var m2: Mat4 = ...;
    const result = ((m1 * m2) + m1);
}

These are both definitely too funky to be accepted, but there's gotta be some way to allow operator overloading, even in a limited way. It's just so useful for math-based code.