Can I use 2 FM-2030 HD Handpieces at the same time?

This depends on what the FM-2030 is connected to:
If you are using the FM-2030 on the FM-203, the answer is no, you cannot use two FM-2030 Hand pieces at the same time.  
In fact, you would not be able to use the FM-2030 with any other hand piece that is connected to the FM-203.  This is due to the power consumption of the FM-2030 with the  T22 Series tips.  This is similar to the situation when using the FM-2022 or FM-2023 on the FM-203.  When using these hand pieces, only one of the handpieces will be able to be used.
Now If the FM-2030 HD iron  is connected to the FM-206, the answer is yes, you can use two FM-2030 Handpieces at the same time.  The FM-2030 can be connected to Channel 2 or Channel 3 of the FM-206.  Both of these channels can provide 140W of power output and with the capacity of the FM-206, you can power 2 hand pieces simultaneously.