The MikroTik RB5009UPr+S+IN supports SFP+ connectivity, which typically includes compatibility with SFP+ DAC cables. However, specific compatibility with 25G flexoptic Passive DACs and FS switches with SFP28 ports is not explicitly documented in the available information. It's advisable to consult MikroTik's official documentation or contact their support for detailed compatibility information regarding these specific DACs and switches.