You can Re-Destill with a Preflight component. I have attached a .kfpx file which you can add to a Prelight Component in FF Core. You need to add this as a Process Plan. See screen shot. Then you can use this Preflight Profile whereever you need in a workflow. If you set a Save component after this, you can save the new pdf. I have used the Press Quality setting from Indesign for the PDF Conversion. This will save the PDF in PDF version 1.4. You can of course set up a Process plan using other PDF settings.
To create or change the process plans you have to use the PDF Tool Box from Callas Software. Xerox are using their preflight module within FF Core. See the two screen shots at the bottom.
I have tested this on FF Core v. 7.0.4 but I think this Process plan will work in the version 7.0.3 as well.
I hope this will help you.
You can do this using pdftops.exe in an external process.
Then save the resulting postscript into a hotfolder of another workflow, so the postscript will be converted to a PDF again.