What you want IINA to do:
I would love for IINA to adopt drag-and-drop support for m3u, m3u8 and similar playlist files.

What IINA does currently:
This is my setup:

• IINA 1.3.5 Build 141
• mpv 0.35.0-419-gf79458476b-dirty
• FFmpeg 6.0
• macOS 15.2 (24C101)

In my case, I have m3u8 files with references to a bunch of local mp3 files. No remote sources are referenced in these.

I can open these m3u8 playlists via the "Open..." dialogue. I can open the mp3 files either via "Open..." or by dragging and dropping them into IINA (either anywhere onto the launch window or onto a specific position within the queue).

I cannot drag and drop playlist files at all, even those created with IINA. I could reproduce this missing feature with m3u files as well. Not sure about other playlist formats.

Why you think this should be added:
I'm suggesting this because it would lead to more consistent behaviour.

Examples of other projects that have something similar:
VLC Player already supports this.