Work parts

It's beginning to feel like this is a necessity for collaborative works, especially those that are multisource and/or contain many Source tags.
I've not yet discussed this with our development team at all yet, but because this also feels to me like an important yet nuanced feature, I want to bring this up for public discussion.
Some initial thoughts on this:

• Parts can be an extension of their defined relations.
  • The reason for this is we're already relating Collab Parts, entered as separate works, to the original collective collaborative work, when they exist.
  • When the relation type is a Collab Part, the existence of a work would now be optional (since not every collab part is uploaded individually).
  • A timecode is added as a field for Collab Parts. From the database side, the collab A of the A<->B relationship could be the row that holds this. The inverse relation row would not hold this info, and the inverse row would not exist at all if the separate collab part work does not exist.
  • Based on the timecode and the number of collab part relations, this automatically determines the number of parts and the duration of parts. I believe if there is a circumstance where, say, a collab part is uploaded in different forms (i.e. audio only, different visuals, etc.), these should live under a single work, and tags can be added to that work to classify them as such.
  • This allows metatags, like collab_parts:>0, to function out of the box.
• Tags on a work can connect to Collab Part relations.
  • Source, Creator, Media, and Song, or rather any tag that is a Source or can be marked as a sample, even if not marked as a sample, could connect to Collab Part relationships (note the plural!).
  • If a Source tag applies to all parts, it would be expected to NOT connect to a Collab Part. This would be to handle tags such as medley song tags, overarching source material (i.e. Gachimuchi), or creators whose parts are unknown or they play a Director role but did not contribute to any actual parts. We may want some sort of flag to denote a user willingly made this decision, but fundamentally we want this ability to have some Source tags be considered applicable to the work as a whole.
  • On a work's main page, in addition to the standard flat tag view we have currently, a new view option ("Timed"?) would be available to show the aforementioned tag categorizes by part, with the timecode shown.
  • As part of this, the "Tag" tab would likely be deprecated, and tagging functionality would move into the "Edit" tab, to make editing all this connected information easier.

One question this feature could raise is, could we define timecodes for any tag at all? I'm still uncertain of this because of how granular this could be and the created workload in moderating this info, but am open to thoughts on this. Let's try to keep discussion here focused on specifically this feature of defining parts of a work though.