I did it once in conservatory many years ago using Soverign Porcelflex Rapid then mixed in with sbr, I have been to the house many times for other work and it's still sound...not somethink I do nowadays.
I have done a quarry floor for the owner of a small cafe once about 15 years ago using wickes rapid floor adhesive not flex onto stirling board he supplied everything,did not want to do it bbut he was a friend and I told I would not be responsible if they lift of which he agreed,that shop has exchanged hands a few times and the floor is still solid.