IPTC editor workflow

I like the idea of adding my captions and keywords in Capture One but I am finding the IPTC editor almost unusable. Before I create a support file, I would like to know if others have the same problem or am I just doing something wrong.

Here's an example of my problem.

If I select a number of captioned images to add keywords and the "add Caption Box" is checked, all the captions are changed to that of the first image of the group I selected...
If the "add Caption Box" is unchecked, all the caption info on all the images is deleted.

The way this works, there is absolutely no way to make batch adjustments without losing information that may be specific to one image. Do I have this right?

Thanks,

Rick