Compound clips timecode workflow

Ok, been racking my brain around this issue and hoping someone can help.

I have 5 reels that are compound clips. They are on a timeline that starts at 59:49:00:00 (so I can do a proper ten count and 2pop).

What I'd like to do (since i'm swapping music cues with my composer) is have timecode running inside each compound clip that will correspond to the timecode of the whole sequence. My idea was to put a timecode generator and then adjust the offset to match the timecode the clip starts at in the main project. Sounds logical right?

So, I would (for example) see that Reel 3 started at 01:36:47:16 in the main project, then I'd click into the compound clip, add my timecode generator on top and adjust the offset to 01:36:47:16 - thinking that then the timecode generator would start at that.

BUT NO!

For some reason, when I adjust the offset, the timecode reads 02:06:07:11!! And it's boggling my mind. Anyone? Bueller?

Put the TC generator across all CCs in the Project timeline. Then draw a range and export only what you need at the time. It won't give you TC inside the CCs, but, for a simple export it works. Again, you won't have the reference inside the CCs. But if you muted everything except the TC generator, then exported that, import the resulting ProRes Proxy (no need for high resolution, its just numbers), and edit that into each CC. But then, its static...

That's a good idea for a workaround, but I still don't understand why the offset isn't working the way I thought it would... very annoying.

I've not tried it, but I'd fill out the feedback page and let Apple know.