Adobe PDF Pack has its own user forum at https://forums.adobe.com/community/createpdf
I would post a message there as most people responding on this Forum have the full version Acrobat Professional and may not be familiar with the PDF Pack.
PDF Pack has a dedicated user forum.
If the online subscription service does heuristically tag output PDF do expect to have to do a "fine scrub".
It will not be better than Acrobat Pro's programmatic tagging.
And while Acrobat Pro's "Add Tags to Document" can get the PDF in the ball park for basic content more complex content generally lands out in the parking lot.
That's not necessarily a bad thing as being "on property" can often be a good starting point.
PDF Pack has no PDF editing tools at all and will not help with tagging. Definitely a job for Acrobat Pro, and considerable study and patience...