The sensitivities of the subs will be different running at different impedances. The drivers running at 1 ohm are going to draw more power than those running at 2 ohm and overall power consumption is going to be more--the output will be up to 3db greater for the lower impedance subs, depending on the amp's capabilities to run at lower impedance. You can adjust the gain and calibrate the SPL for each sub to match the sensitivities but the lower impedance systems will still draw more current to reach a certain amount of wattage while running at a lower voltage (Ohm's law). You're 1 ohm setups are going to be running hotter with more current and the amp will wear faster than with the 2 ohm setup. Furthermore, the amplifier damping factor will be different for each setup. The 2 ohm system will have 2x the damping factor of the 1 ohm system, meaning it will tend to play with less distortion and have better transient response at higher power levels, but it will not match the 1 ohm driver in overall output.
So I guess it is OK, but it is not optimal.