Answer
Yes, you can use the PTS Firmware on the BL654 Dongle, but it's important to know which version of the dongle you have. There are two variants:
Only the 451-0004 (Nordic version) can be used with PTS Firmware.
Note: Once the PTS firmware is loaded onto the 451-0004 (Nordic version) BL654 dongle, it cannot be reverted to its original "normal" mode. This process is irreversible, and the dongle will remain in PTS mode.