I don't know your skill set, I don't have a totally clear understanding of your goals, so If I get this wrong, please understand.

So, per my understanding:

I would, if it were me, first save the project. I would then render whatever it is (composited section) that you seem to like, and render it, perhaps, a couple of ways, one as large as practical, or original size - then the second to a targeted pixel size, the new size you mentioned, or whatever size you'd see as appropriate towards your purposes. NOW USE (probably) THAT FILE in the timeline. (or even a new timeline if appropriate) Mute/hide or delete the original compositing tracks and save the project again with a new name. The alternate (larger) rendered file is so you can manipulate in different ways if need be.

So, now you have the original project saved in order to REDO the composite if you need to, and you have a second project, sans those compositing tracks, to move forward and not worry about compositing, as that obliterates your resources for playback.

Although I absolutely wish I could say otherwise, I have never found the nested project implementation bullet proof, thus I don't trust it, thus I don't tend to use it nor recommend it. In your case, it seems quite unnecessary tbh.

Let me know what you think about this or how it might not be suitable if that would be the case.

Thank you all for the tips!

Seb-o, indeed, this is how I'd usually proceed, have a rendered file that's then easy to manipulate, and for preview speed's sake.
I was just wondering if there was a way to do it with a new parent track, so I'd be able to change things in the child tracks on the spot if needed.

I found it kinda strange that the parameters on the composited tracks changed as soon as I childed them to a new neutral parent track.

Having said that, I think it would be a great thing if we could have FX etc on the track group as a whole / master track. I know we could use the adjustment track, but it would be quite practical IMO.
 

"Having said that, I think it would be a great thing if we could have FX etc on the track group as a whole / master track. I know we could use the adjustment track, but it would be quite practical IMO."

Actually this should work. Could you share a simplified demo project which shows the issue?

Hey Marco

long time no see 😎
well when you collapse the track group, the only visible icon / option remaining is the group mute or unmute. What I meant is that it would be good to be able to treat it as a normal track with all its options, like FX, composite etc.It would then be sort of a master or adjustment function.

I think I see. So it is "Grouping" vs. "Master-Child-Compositing".

Yes, Grouping is a pure interface layout option with no functional purpose. And vice versa Master-Child-Compositings are pure functional with almost zero layout options.

And you probably want the Child Tracks to collapse related to their Master Track (without losing the Master composite controls) so complex Master-Child-compositings would appear much more tidy.

Yes, exactly, that's the idea.

And you probably want the Child Tracks to collapse related to their Master Track (without losing the Master composite controls) so complex Master-Child-compositings would appear much more tidy.

@Marco. an excellent idea!

Group the tracks. Then add a new video track above those tracks. Then make the first track of the group a "child" of that new track. Done.

That's what would be the most logical and easy solution and what I tried, ( see my OP )
but for some reason, the compositing parameters of the subtracks change as soon as they are child tracked to the new parent. ( Like the pan crop positions get put back to center for example)

I'll see if I can make a video later.

So I found the "problem". Turns out it wasn't really one.

What happened was that upon childing the first of the composited tracks, only the first part of the compositing changed, because I didn't add the underlying track to recompose the original frame, which made me think that the new parent track changed the compositing for some reason. ( see video)

Now that I kept childing the other tracks, like I usually do, things went back to where they were intended. I just stopped to early as it seemed weird that the composition suddenly changed.
At first it didn't make sense to me that it didn't work as it used to, and some of you rightly pointed out that it should follow the simple logical procerdure that's usually used for creating a master track. Well it actually does.

Sort of a silly mistake, sorry about the confusion.

@Mindmatter Hi, try this see if it works?

Add a new track that's going to be the main Parent,

Click the top track of your group,

hold Shift & click the last one thereby selecting all,

Then Child that selection to the new Parent track,

All Parent/Childs stay intact, in the order they should be 👍

Very cool, looks like quite the time saver!

Thanks Gid!