The UFM in Max II have very less write cycles (less than 100 right out of my head) see datasheet.
we were realy unlucky with the UFM and accessing it via spi was very unreliable.
no matter if spi clock was 4MHz nor a few kHz. the spi signals had no over or undershots
so we used 1 UFM as a mirrow of the other UFM as a fall back memory. but it happend so often that after power up both UFM delivered garbage via spi or the whole memory content was corrupted. thats why we decided not to use this UFM memory anymore.
Our EPM570F100I5N talks with a EP2C70 via SPI, the 3,3V power supply is impedance controlled and stable external reset works the hdl inside max ii works but ufm not always.
Same situation no spi command sent to max ii, just a power up.