MOR table log file write in append mode or update mode?

For the MOR table，

There is record (id = 1 , name = A0) in the base parquet file, then
1. I update the record, the record will write to the log file（id=1， name=A1），
2. I update the record again，id=1，name=A2,

My question is id=1,name=A1 and id=1,name=A2 are in the same log file（append write）？ OR id=1,name=A2 overwrite id=1,name=A1, that is, id=1,name=A2 will update id=1,name=A1 in place?

No file, test, or entry point is named. Start by locating the MOR table write path and its log-file documentation, then verify how repeated updates are stored; done means documenting a definitive answer for the append-versus-in-place question.

Written by the indexing model from the issue text.