The main thing I'd be looking for is negative feedback resulting in a stable system. For example, increasing PRL --> decreasing T --> decreasing E2 --> decreasing PRL. This is partly why we get into trouble with TRT. This natural regulation no longer exists.
Regarding prolactin, as with most hormones, too little or too much may be a problem. Read this page: https://www.peaktestosterone.com/low_prolactin/
I am not a medical doctor; any suggestions are meant to be discussed with your doctor.
Age: 59, Ht: 5'10", Wt: 154 lbs
Protocol: 2.4 mg T propionate subQ qd, 3.2 mg T enanthate qd, 20 mcg GnRH subQ 5.25x/d, 6.25 mg DHEA bid, 12.5 mg enclomiphene qod
Approximate levels (peak): TT: 700 ng/dL, E2: 30 pg/mL, DHEA-S: 300 ug/dL, SHBG: 30 nMol/L