I think you are asking if the Cosmic Microwave Background (CMB) can be used as an absolute frame of reference for the objects in the universe.
Over a period of observational years we can get an idea on the density of the CMB to create an image like this:
However, this is an accumulation of samples that have reached us during the few decades we have known the CMB was there and recorded it. If you are looking at a GRB 5 billion light years away or a type II super nova 300 million light years away you are getting a high resolution image of a specific local event that happened 5 B or 300 M years ago. But the CMB is everywhere in the observable universe and faint at about 2.73 K.
We can make some assumptions based on CMB we can see now, but between expansion, gravitation effects, and time we can not rely on the CMB as being a absolute reference frame, as what we can see now does not necessarily indicate what changes the CMB is going through the farther away it is.
So the CMB is A frame of reference, but not THE frame of reference. As shown by Special Relativity, every frame of reference is equally valid. So if you are observing from different relativistic reference positions the CMB is going to appear to have very different wavelength, directions, etc. The following is a image showing red shifting and blue shifting of CMB reaching our detectors…its obvious the CMB is not simply spreading symmetrically from a “central point”.
CMB red and blue shifting, density, rotation are going to tell us more about relatively local areas of space, ie. the rotation of our galaxy or Andromeda and the Milky Way moving towards each other at a closing speed of ~ 110 km/s, but the farther away an object is the less information the CMB can tell us about that object’s relative motion to it.
Bottom line: CMB is a useful frame of reference but not an absolute frame of reference that would allow us to pretend that it is THE resting position of the universe. Areas of the CMB are in motion relative to other areas of the CMB, even after accounting the fact each part of it is moving at c.
https://www.quora.com/Why-cant-the-CMB-be-a-universal-reference-frame
From the CMB data it is seen that the earth appears to be moving at 368±2 km/s relative to the reference frame of the CMB (also called the CMB rest frame, or the frame of reference in which there is no motion through the CMB).[84]
The Local Group (the galaxy group that includes the Milky Way galaxy) appears to be moving at 627±22 km/s in the direction of galactic longitude l = 276°±3°, b = 30°±3°.[85][86]
This motion results in an anisotropy of the data (CMB appearing slightly warmer in the direction of movement than in the opposite direction).[87]
From a theoretical point of view, the existence of a CMB rest frame breaks Lorentz invariance even in empty space far away from any galaxy.[88]
The standard interpretation of this temperature variation is a simple velocity red shift and blue shift due to motion relative to the CMB, but alternative cosmological models can explain some fraction of the observed dipole temperature distribution in the CMB.[89]
https://en.wikipedia.org/wiki/Cosmic_microwave_background#CMBR_dipole_anisotropy