Has anyone had benign cysts on kidney?

Hello,
When my spouse was diagnosed with CKD it was shared that he had two benign cysts in his right kidney. One that was 5.3 x 4.6 x 4.1 cm and one that was 1.3 x 1 x 1.5 cm.
I had asked his Nephrologist at that if that was a contributing factor and have asked a few more times, and they said "No". and said that they they were not an issue.
He has declined from stage 3 to stage 4 what I feel is a short amount of time. Within in year.
He has stage 2 Diabetes and High Blood Pressure, which has been in control especially within that time frame.
I am thinking of finding another doctor and getting a second opinion about the cysts.
My long story/background is to ask, has anyone have benign cysts and what did your doctors do about them?
**They never biopsied his kidneys, the doctors say that his CKD is likely due to early uncontrolled diabetes.
Thank you.