I decided to give the Dash trial a try...and the thing I was worried about is already happening or will happen...--> The AI tag limit will be reached almost immediately if one has quite a few asset packs installed in a project. I presently have 14 asset packs installed in my present project (with a total of 6854 assets in those so far) and I'm just getting started with my asset packs. Even with the ability to filter the materials...that still will most likely exhaust the monthly allowed almost immediately. One of my asset packs has over 1000 assets in it alone...others are similar.
Giving this a bit of thought, why not integrate the Dash content browser into the Unreal Engine content browser for the installed asset packs. What I mean is give us the ability to highlight any assets in a UE asset pack folder in the content browser and then select those assets for computing/tag in the right click pop up menu that UE already provides. Add an 'add to Dash or tag' icon or similar in that menu. That way, we can have total control over what assets to include for tagging rather than just computing the entire folder with assets we may not use (this would go a long way towards limiting the already low monthly asset allotment).
If that is not doable then have the dash content browser (project library) recognize and show the assets in the dash content browser for the user to then highlight the ones they want for tagging. Either way, the user will then have control over what is tagged instead of just tagging the entire folder thus eliminating tagging of unwanted assets. Cheers!!!