quantum mechanics - What Planck units are limits?

Some Planck units, like time, length, or temperature, describe a physical maximum or minimum, at least approximately: you can't get hotter than the Planck temperature, measure anything smaller than Planck time or length, etc. Others, like the Planck charge, Planck momentum, or Planck energy, seem to have no associated maxima. Which units are of what type, and is there a reason that some are limits while others are in the 'middle' of a spectrum of possibilities? Are there limits to physical units which are distinct from the associated Plank unit?