I just bought this example from Aquileia with an X in the pediment.
the dealer description...they call it a cross in the pediment.
Maxentius (306-312). Æ Follis (25mm, 6.17g, 11h). Aquileia, 307-310. Laureate bust r. R/ Roma seated facing, head l., in hexastyle temple, holding globe and sceptre, knobs as acroteria; cross in pediment; AQΓ. RIC VI 121a. Good EF