They are not going to make Egis the size of the Primals, or even half their size. It's impractical from a screen space point of view and would obscure a great deal of critical information, to the extent that Summoners would basically be excluded from raiding.

What you may see happen is Summoner call forth a full size Primal for LB3 when job-specific limit breaks are implemented in 3.0, but that's about it.