The way I understood it, was the VEFR was an offensive ECM platform, actively fighting the enemy with ECM weapons. The Elint was more passive in it's role like a AWACS in keeping comms and formations together. Kinda like one jamming the enemies missiles and radar while the other coordinates the attack.
BTW, the VEFR does have a head under the dish similar to the Elint, but can't do FAST packs. That probably means it could fly in atmosphere.
The VEFR is based from a VF-1A-J-S frame with a VF-1D nose, while the Elint is based from the Ostrich.