I’m sorry you have this worry.
Although the chances of MGUS developing into myeloma are only 1% per year, rising amongst older people, but still to just 5% a year, it is a worry hanging over your head. And the reason for knowing is to have occasional blood tests to check that there is no evidence of a rise in paraproteins. Personally I would press for repeat tests just in case you have a variation called MGRS, monoclonal gammopathy of renal significance. It’s still unlikely, but I would want to rule it out. With these blood disorders we have to become advocates for ourselves and it takes a bit of getting used to. I hope your kidney issues resolve.