Hi Joe,
Thanks for your request, we understand and feel your frustration.
Unfortunately there is no simple answer for this one.
The manual is available to and it's location published to Google in our site manifest to make sure that Googlebot can find it.
We do not stop Google from indexing it.
Google has a limitation on the size of PDF documents it indexes. The DaVinci Manual exceeds this size and hence does not get included in a Google search (since Resolve 15).
Many of the competing search engines use the Google seach index metadata and similarly do not find the manual for this reason.
A possible solution is for the manual to be broken into sections contained in smaller files that can be indexed by the search engines; this however would require multliple downloads to fetch the complete manual if it is to be available to Google to index i.e. it can't be broken up and then zipped into a single download for users to download.
Regards,
Martin