Now, g1-migrator provides the JSON of all Ğ1v1 transactions history converted into indexer V2S format: https://g1-migrator.axiom-team.fr/indexer/history.json (41MB)
The addresses declared here are switches as expected.
This is update every days.
Maybe some multidests transactions are missed due to my script, you can check.
The data comes directly from the Duniter SQLite db
txs.db, as @elois suggested to me.
sqlite3 txs.db --json "select time,comment,issuers,outputs from txs;" > transactions_history.json
Here is the script for converting the input data: generate_transactions_history.py · master · tools / py-g1-migrator · GitLab