I suggested a single flute end mill because smaller machines may not be able to move fast enough and/or reduce the router RPMs enough to get a good feed rate with a 2 flute bit.
A single flute bit has a much larger gullet for better chip disposal.
A tool with more flutes has less space for chip disposal. However, bits with more flutes are stronger. That is one of the reasons bits with 4 or 6 flutes are used in metal.