@Anonymous It seems to me that there is something wrong with your reply.  I am running QB 2019 R15 on my macbookair M2 OS Sanoma which should not be possible according to your response.  I stll have not upgraded to Seqquoia because I had problems last year when I initially uploaded Sanoma and QB crashed, but after a while patches became available and Sanoma loaded and QB ran.  It still does.  Maybe you can expand your answer and let me know why you think my QB 2019 R15 will crash if I upgrade to Sequoia.