This is a simple customer satisfaction issue.
If my dealer told me no when I asked for the recode, citing a BMW request that I try it out for a few weeks first, I would have complained. I'm not a child. Leaving the showroom on Day 1 with a homework assignment and the need for a scheduled appointment with the service department before I even got into the car would have annoyed me.
Last User Mode is analogous to memory buttons for seat adjustments and radio stations; it just makes sense.
And FWIW I tried ASS and am not a fan. I default to OFF. Easy.