Yup - PagePlus X3 will search and replace (ctrl-H) within the text of a pdf file (provided the text is not part of an image).
That's potentially invaluable. Thanks for the research! PagePlus does so many other things I wasn't sure I'd want to bother with it, even though it's a bit cheaper than InFix.
X3 does offer to open pdf's by default (ie pdfs are listed as PagePlus files in the Open dialogue) but once a pdf is selected to be opened, it is imported as mentioned above. To save as a pdf you have to select "Publish as PDF" from the File menu.
You said import was a little kludgy. That could be a problem, but the PDFs I have to edit are (at least, look) simple in form, mostly text with a few small graphics. Can you print direct from the ppp file? If so, then you could print to any PDF printer.
I found something that claims to do multiple search-and-replace within PDFs: PDF Text Replace Tool
but it needs both MS Framework 2.0 and
Visual C++ , and costs $49. I was baffled by the Visual C++ requirement, which only appears when you try to install it, it's not obvious on the Web site. Because I don't have Visual C++ and don't know what's involved in it, I didn't proceed any further.
Nuance annoyed me. I live in the UK. I went to their "Buy Now" page, which says the price is US$99.99, about GB£62.5, then changed the country to UK. The price turned into £99.99 - which is over $159
Admittedly that includes tax at (currently) about 15%, making the price more like £85 or $136, but I wasn't going to pay so much over the odds just because I live in the UK. It's a connected world now, and Nuance and other vendors will have to accept that. I bought a license for Able2Extract instead.