LOM - Track.is_foldable does this property work correctly for Rack-Tracks yet?

Since both Max 5 and the current documentation say this about the Track class's is_foldable property:

1 = track can be (un)folded to hide or reveal the contained tracks. This is currently the case for Group Tracks. Instrument and Drum Racks return 0 although they can be opened/closed. This will be fixed in a later release.

My assumption is this mythical "later release" has NOT arrived yet, because the error message breadcrumbs I'm following led me straight to "is_foldable".

Is it really still true an Instrument or Drum Rack Track's "is_foldable" property returns 0 even though "Rack Tracks" can be opened/closed?

How do M4L coders work around this issue?

How can M4L otherwise detect a "Rack Track" in the Live session?

Specifically, how can a patch tell if a "Rack Track" is opened or closed when it can't access the fold_state property because "is_foldable" returns 0?