This has been my understand as well. I have CKD and my doctors have always been chill about it as long as I stop taking it about a week before having blood work done.
EDIT: I don't do 25g though... sounds like a lot...
If your egfr is above 80 it’s you won’t notice it. But CKD is a late in life problem so you are basically making your end of life worse by making your kidneys work harder now. You might as well take up smoking: claiming it doesn’t hurt now is a lot different to 20 years of constant use.
You're lucky your doctor is aware of it. I've had several who did not understand, and insisted creatine must be dangerous if it elevated creatinine levels, and/or didn't understand the effects.