I apologize if this sounds mean or rude, but I was always of the belief that Ifrit's appearance in the benchmark trailer was a trick of the camera at best, or intentionally done to promote the game at worst, so I would say don't get your hopes up. A very, very long time ago the developers said they have no intentions of making Egi any bigger, so I find it hard to imagine they would go back on that now by making larger glamours.