My wind data is in 10 minute increments and I’m wondering if I will have to synthesize it if I would like to go down to single minute time steps? Or is that something HOMER does automatically?

If you import 10-minute wind data and then set the simulation time step to 1 minute (in the System Control Inputs window) HOMER will simply chop each 10-minute wind speed value into ten identical 1-minute values.  So the wind will remain constant for ten minutes at a time, but HOMER will still simulate each 1-minute time step separately, and it may, for example, determine that the flywheel runs out of energy in time step number 7 and it needs to start a generator as a result.