I bought the K-7505-VS for my kitchen December 29, 2021, my contractor installed it end January, and it stopped working properly 5 weeks later.  The black buttons stick and impede water flow.  Kohler is sending a replacement spout and assured me with the lifetime warranty it won't be a problem to get the replacement part if it happens again.  But what happens if they stop making the faucet (which they should) and the part is no longer available?