The timing is the key to this step. The block has to be thrown on a half count meaning it is thrown as you are moving forward rather than when you are grounded. The reason for this is to keep the power of the movement associated with the punch.
We demonstrate both a straight line forward stance as well as the angled froward stance. It is important to work and be comfortable with both of them. Also, practice both the half moon as well as the direct step variations.
A properly timed punch with your forward step can be extremely powerful. Driving through and extending the back leg drives the hip forward and puts almost all of your body weight behind the strike. Though it is a very committed movement, it can have finishing type power when thrown correctly.
The inward block will the focus here because it is the most common block to throw from this stance, however you could also practice your other blocks. The key is developing the right timing for the block and step together.