I have a Mathews VXR 28 and was curious if anyone else has bow and your stabilizer setup. I currently have a 8” trophy ridge stabilizer in front but thinking of adding a rear stabilizer. Never had one on a bow.

You shooting targets or hunting? If hunting, there's absolutely no reason for one IMO

if you want the smallest pin float you can achieve,you absolutely need a rear bar. I hunt with a 15 inch out front and a 12 in the back. without a rear bar you are going to get vertical pin float with is bad on an animal that walks on 4 legs and is horizontal. you have more room side to side than up and down. shootingba compound bow is the art of being still that's what separates the pros from the amateur. the pro has mastered the art of being still. your stabilizers are crow bars they are leverage to resist your movement. your bow should be balanced on both axis start with 3 oz up front then put enough weight on your back bar so that your bow doesn't tip forward. then move back bar in and out from string till it sits still straight up and down and does not tip side to side.
accuracy is what kills any thing you can do to better achieve that is necessary.

I used a 6” B-Stinger MicroHex with 3oz of weight on mine. A rear bar definitely helps, but for hunting purposes, I shoot well enough without one.