If the EJ205 was bored to 2.2L, that's your answer right there. The extra displacement is less the reason for the torque on the 2.5L as the longer stroke. For example, a 2.1L stroker motor (EJ205 case and EJ25x crank) will produce a similar powerband as the 2.5L with quicker spool compared to the EJ205. Increasing the bore without addressing the stroke is good for an exceptionally high-revving motor, which is usually counterproductive to producing low-end torque. AVCS surely doesn't hurt torque output down-low, but a higher CR 2.5L hybrid will produce more torque (more cylinder scavenging) than an AVCS-equipped 2.5L EJ255/257 with similar modifications.