Sorry for getting in your discussion. I think you misunderstanding the hex code structure, which may result bios setup in being broken.
The first byte you replaced with FF (byte 03) means the number of values inside question’ list.
3 in total [0, 1, 2]. Replacing it with FF indicates that the question now has 256 values.
So the related opcode with your edits can be interpreted as
EqIdValList QuestionId: 0x2CD9, Values: [0, FF, 0, …, 0.]
Although Uint64 Value code can have any 64 bit int number, SuppressIf consumes only boolean values. But for SuppressIf it’s going to be the same as True (0x1), so Uint64 Value: 0xFF is a valid edit.