Issues outputting alpha channel (From clips where opacity was changed in Premiere)

Hi,

I'm conforming my cut for a colorist. They want all alpha channel videos to be ProRes 4444 with alpha.

I am having trouble with any videos that did not have an alpha channel when originally imported into Premiere (i.e. with clips where the transparency was created in Premiere.) As an example of what DOES work, my chyrons that originally had an alpha when they were imported will output with an alpha. But I have videos where the Opacity was changed in Premiere or I've used the Screen Blend Mode in the opacity setting. These videos are not being output with an alpha channel. I've done the normal trashing of files and restarting several times. New projects. New sequences. One thing to note, a render and replace can be used to get the codec changed, but since it doesn't give an alpha channel it's not working for my needs, because the colorist wants an alpha channel and these "render and replace" files are still using the Opacity settting I have applied to the clip in the timeline.

How do I get these opacity and screen mode altered clips to output with an alpha channel in ProRes 4444 how the colorist wants them? 

Thank you for the help!!!!

Thank you!