I’ve just worked on 3 series last year with lots of subtitles on every episode.
Working them into our Baselight workflow was and is a nightmare.
I couldn’t use the subtitle track function, as I would then not be able to export them back out to grade as you mention above.
I imported them as a standard text layer which worked fine. Was then also able to colour manage / adjust them to correct level for HDR or SDR. I can’t remember about the clamping when using subtitles track, will take a look soon.
Where it all falls down for me is getting them back out of flame with an alpha. I’ve raised tickets with support and they can replicate the issue but they don’t look like fixing it any time soon.
Ended up having to mix them all down then sequence publish them out…
Does that help in any way?
Definitely something that made me hate flame recently.