HP Tuners is VIN, OSID, and PCM Serial Number locked among other things unless you have purchased the unlimited vehicle license for the specific model year of car and type of engine you are working with.
If you have only used 2 credits to license your car/vin, I doubt you are going to be able to flash your PCM with a different .bin file unless that .bin file has your VIN and the same OSID number you are licensed to work with. Otherwise, you could get a VIN/OS mismatch error and HP Tuners will not allow you to reflash the PCM.