*What kills you and takes up time is the Raytracing and Shadows.
I personally feel that they make the render look worse anyway.
What I think really improves renders is lighting: that is...make it BRIGHT.
Have the same settings for everything and use dark lighting for the render.
Then render it again with brighter lighting.
Depending on the mood you want to convey, I feel the brighter lighting brings out more detail to the renders. You can get away with removing some of the spiffy Firefly features if you make sure your lighting is good. Since you're probably using Poser as a hobby and not as an industrial tool, not having Raytracing isn't going to affect you too much for most renders, although there will be times that you'll want some shadows.

I wish you had a gallery to back up these statements. * So, I won't bother

To the op,, Setting shading rate to 0.00 (100 micropixel calculations for every pixel.. at least it used to) or, setting RayTrace "bounces" high (more than 3 0r 4) will stop time as we know it.. especially if you have transparent materials loke glass os hair... just an example..
I think you only need 3 bounces to get refraction.. *