In a very recent question: "Más me gusta X entonces Y" construction, a comparison with the following structure is used:
Más me gusta X a Y.
Until now, I've only seen "a" used in comparisons (though it is debatable if the following is a comparison at all) with the verb "preferir":
Prefiero X a Y.
However, for "más" / "menos" comparisons, "que" is the only preposition that applies, as far as I know:
Me gusta más X que Y.
Corre menos Z que W.
Even if the verb is placed in between:
Más me gusta X que Y.
Menos corre Z que W.
Is it correct to use "a" in place of "que" in comparisons with "más" / "menos"?