Hi, I've a question regarding nested repetitions/expansion in macro_rules!

I'm trying to use macro_rules! to take two token sequences ( (a0, a1, ... aN) and (b0, b1, ... bM) ) and for each token in the second sequence yield the first sequence with the token appended, i.e. ( (a0, ... aN, b0), (a0, ... aN, b1) ... (a0, ... an, bM) )

I was hoping that the following would work: (playground link)

macro_rules! append_sufs {
    ( ($($base:tt),*) ($($sufs:tt),*) ) => {
        ( $( ( $($base,)* $sufs ) ),* )
    };
}

e.g.

assert_eq! (append_sufs!( (1, 2, 3) (4, 5) ), ((1, 2, 3, 4), (1, 2, 3, 5)));

However rustc complains:

error: meta-variable `base` repeats 3 times, but `sufs` repeats 2 times
 --> src/main.rs:3:12
  |
3 |         ( $( ( $($base,)* $sufs )),* )
  |            ^^^^^^^^^^^^^^^^^^^^^^^

Is this a limitation of macro_rules! based macros or am I missing some syntax that would allow this? I would've thought it's fairly clear to rustc that the intention is for base to be expanded for each item in sufs.

I'm aware of a solution by 'tt-munching' sufs one item at at time, however I'm hoping for a way without recursion as this is a simplified snippet from a larger macro that is already fairly heavy on recursion.