how to generate random and limited 128bit SUID key?

I'm doing some random generation of 128bit ID's in range between 0x00 and 0xff and I'm wondering which one of my 3 samples is superior (if any) aka if I will run each method x-times, which one of those will give me more unique ID's in a long run, and/or also which one will be less faulty in case of repeatings.

D2 ? D3 ? or D4?

I'm including my sheet because my formulas are very long: https://docs.google.com/spreadsheets/d/1O1B8R5MkKr9QNF2F3qskUVmAMQGhXOQBm7O8VifFFiM/edit?usp=sharing

my guess is that the weakest is D2

also... is it worth to do D3 over D4 in the name of more randomnes/originality? or is there even difference if I use RAND() in a first place. (I cant really tell if I probably dont see something what isnt there...)

??