"as if the Save Records as PDF script step is rendering as an image rather than as a vector like the PDF that I placed into my container field."
This is exactly what it's doing. The PDF rendering engine is capturing non-text content as an image. It doesn't embed your container contents as its own separate object in the PDF. Think of it as a screen capture instead of an embed.
You may be able to play with adobe acrobat preferences for the image settings for PDFs, however you may want to try alternative methods too, like using a webviewer instead of a container field.
You might also consider these options:
Don't use a PDF in a container field to produce another PDF. Set up your layout to present this information using either layout text or (better) text in a field or fields. Then you can save as PDF and append as needed.
Make this PDF the start of your PDF'd document. Export it to the temporary folder and append your other data to it instead of the other way around.
From your comment, it appears FileMaker doesn't do its own PDF rendering but instead farms it out to whatever the default PDF reader app is on the client. Do I understand correctly?
The T&C document is something that comes from legal as a Word doc, and I convert to PDF. But I suppose I could just import the text into a text field in FMP and then try to format so it mimics the original. Might be easiest way to go.
Why would I want to start with my T&C doc and then append the estimate page after it? That would set my main estimate as page 2, which is not where I want it.
PDF is still a proprietary format, so that is correct. It is most likely using external libraries, rather than having written its own.
That's a bummer because there's no predictability about how the PDF will render. I'm in the printing biz, and I use a variety of apps that render PDFs using their own engine. I'm guessing it's something that FileMaker could do if they chose to license the engine or whatever.
Bottom line is I think I'll take Phil's advice and just squirt the T&C text into a text field and format to look pretty.
Thanks for your, help, guys! You rule!
Why would I want to start with my T&C doc and then append the estimate page after it?
You would only do that if the resulting order to the parts of your document were acceptable. If it isn't, you wouldn't.