Workkflow from 4K FCPX project to best quality DVD?

Export as Pro Res LT.

That should work just fine.

Or you can alter the Project Properties to match the DVD specs, then copy/paste the existing Project into it.

That will be either PAL or NTSC Standard Definition

As mentioned the OS in use can affect how iDVD will or won't work.

Provide specifics is you still have problems.

Al

" I do have iDVD, and Compressor and Toast. Just wondering what tool to use. "

iDVD is the most versatile regarding menu and personalisation. However, over the various OS upgrades is has become less reliable. 10.13 should work with some incompatibilities.

I personally have retained an older Mac with appropriate OS for iDVD authoring. 10.8.5.

As regards FCP X DVD authoring, the menu is very bare bones basic. The results are as good as a DVD can acheive. Nice quality.

You may want to consider delivery via an MP4 method such as a thumb drive or media streaming service.

That being said, the end user decides. Where I live there is still a demand for DVD because most people have players. I'm finding that this is slowly changing to the methods above.

Al

DVD quality is always going to look a little soft compared to 4K or other HD media.

There is always the Bluray option if that is applicable.

Al