I'm of the same opinion, Poser needs a realtime viewport which should go hand-in-hand with animation improvements. I've been enthusing about it like crazy in Clarkie's request thread, and for bloody good reason.

EEVEE is the best solution I can think of, but I tried a few weeks ago to find out if it was under the same licence as Cycles, therefore allowing incorporation into Poser, but I got sidetracked and still don't know. If EEVEE is not an option though, I desperately hope they will find a way to incorporate an EEVEE-like realtime viewport, and update the animation tools and timeline interface!