Yes, that is correct. Looking through my notes on when I did this:
Now we can burn the new firmware image to the HCA. Being a HP branded Mellanox card, I have had to let the utility change the PSID from HP's to Mellanox's. Essentially "un-branding" the HCA.
C:\Program Files\Mellanox\WinMFT>flint -d mt25418_pciconf0 -i fw-25408-2_9_1000-MHGH28-XTC_A1.bin -allow_psid_change burn
Current FW version on flash: 2.6.0
New FW version: 2.9.1000
You are about to replace current PSID on flash - "HP_09D0000001" with a different PSID - "MT_04A0110002".
Note: It is highly recommended not to change the PSID.
Do you want to continue ? (y/n) [n] :y
Burning FW image without signatures - OK
Restoring signature - OK