I wrote to a company here in Australia “PUREAU” who claim to have the purest bottled water. They write back and said the systems they used and the way they were steam sterilised before each morning if filtration could not allow mycobacteria in. That is their claim. They told me to give them a batch number and they would send me an analysis of it. I did that but have not heard back from them as yet. However that is all that I am drinking atm and that is all I have been drinking for many years. I use it in my kettle too. Must say the kettle looks brand new inside.
As for pipes caked with biofilm?????? Would have to look into that. If your hot water is high enough it may destroy mycobacteria. I was told by the company that said run if someone tells you they can filter it out that the only thing that can destroy it is heat hot water set at 55 60 heat scalding temp.
I do believe that reverse osmosis under sink can filter NTM out as it’s installed at point of tap and can filter at 0.001 micron depending on filters used. Hope this helps in your decision.