ST has multiple sites doing final test and encapsulation, the frames and equipment might vary.
I would look at the codes for the final facility, ie TWN, CHN, MYS, etc
Also look at the e3 or e4 designations, as these relate to the metallurgy, plating, etc.
The fab code might also be indicative of different die
Something perhaps you could talk to your FAE or sales rep about. And getting on a list for alerts related to parts you are buying.
