Hi, It’s been a while, I was able to got the last 1660s for my last spot on motherboard, bought ir from bestbuy on April 2nd, unfortunately despite of the memory type is Hynix, and hiveos was able to flash the Palit bios with force security check selected, but the Hiveos gave a bunch of drm error during the hiveos bootup and cause CPU softlock, and hiveos panel will display “Unknown” on the memory row.
After went through some newer post regarding to this card and bios version, it seems like the bios 90.16.5A.00.32 is the newer version of 1660s bios from Asus, according to one post from forum: ASUS gifted you with their DRM bios locked TUF 1660 Super, now you can't bios mod those with hynix vram anymore
This might be the cause of those newer 1660s card, I personally got the exact same model this February from Memory Express, that one has no issue to flash the Palit Bios and achieve 36MH hashrate.
Just be aware if you wanna still getting new card, there are posts also said the Asus single fan pheonix version also has this bios version, so I assume that version is unable to do this bios mod either.