Is bytecc ME-340U2F(silver prolific 3507) 's firmware upgradeable

Is bytecc ME-340U2F(silver)'s firmware upgradeable?

I know the similar model Bytecc ME-340U2F- BK(black) 's firmware is upgradeable because the feeback on newegg said yes.
BYTECC 5.25" Black Aluminum USB 2.0/1394 COMBO External Enclosure, Model “ME-340U2F-BK”

I want to know it since the enclosure that i own(masscool 520ui) is not upgradeable even though i tried all of the firmware, romwriter and the romwriter still reject it. and i want to return masscool and get a bytecc.

Have anyone successfully flash ME-340U2F(silver)?

In addition, can bytecc Me-340u2f fit a 3.5 HD using a 5.25 to 3.5 conversion kit?