Limitations

Scroll-speed event scanning

Because of a limitation in the Margrete plugin SDK, Margrete.open_edit() scans for scroll-speed events (TimelineSpeedEvent) instead of reading them directly. This has two practical consequences:

• Events far past the last note may not be read. By default, the scan covers up to 19200 ticks beyond the last note.
• Charts with many scroll-speed events can be slow to open. Dead Soul is a known example.

Workarounds

Use the open_edit parameters described in Edit Transactions to control the scan:

with m.open_edit(
    # ticks to scan past the last note (default: 19200)
    event_scan_lookahead_ticks=1920 * 4,
) as tx:
    ...

Or provide an explicit list of timeline IDs to scan:

with m.open_edit(event_scan_til_ids=[0, 1, 2]) as tx:
    ...

Pass event_scan_til_ids=[] to scan all default timelines (0 through 15) without note-based filtering.

Undo and note deletion

When a Python-scripted edit deletes notes, pressing Undo in Margrete may restore those notes in a duplicated state instead of cleanly reversing the deletion.

Additions and modifications can be undone safely. Only deletions are affected, so note-cleanup scripts should use the deletion workflow in Edit Transactions with this limitation in mind.

Workarounds

• Prefer designs that add or modify notes rather than delete them.
• Use Margrete.undo() instead of Margrete's built-in Undo. It removes duplicates automatically.