Jim - Beyond the pictures on her instagram, I haven't seen any more info about her technique. I did email her about it, but did not get a response.
Here is another pic from her instagram. It's her key lime bonbon which has a key lime PDF. The piping bags are an older pic, so she has clearly changed formulas as it's no longer a red color. I was really hoping to hear from her about her technique, but she was either too busy to respond or it's a state secret. Please note that all images come from here: https://www.instagram.com/kateweiserchocolate/
As for adding puree, I don't think it would take very much to get to a pipe-able consistency. Just a small amount should be enough for the food processor to achieve a good paste. Would have to do the shelf life tests to see the effect. I suppose you could also use a small amount of alcohol to thin it, but that could probably affect the taste.
Vs the texture of the PDF in the finished bonbon:
And here's a picture of a lemon PDF that looks to have a very smooth and fluid consistency: