I have found the search feature, so far, to be less helpful than I hoped. Would it be possible to add the index of the PHB to the info accessible after purchasing it? For example, I tried to look up Darkvision in the search bar but only received information pertaining to spells. A reference to p.184 from an index, which would also then link to the relevant section in the content, would be useful.

The compendium content doesn't have a 1 to 1 relationship with page numbers in the books, so I don't think this would really work.

The search bar on DDB is really subpar. When I need to find something more specifically, I use Google and search site:https://www.dndbeyond.com/ and add any terms I want included or excluded. Results can be further narrowed by adding compendium, spells, items, etc to the end of the url to search specific directories of DDB. It isn't perfect, but it is better.

I agree completely on using Google search - it's the only way to search the large threads on the forums, for example.

Better filtering in search would definitely help a lot of this - right now, all searches on the site need exclusion. You can filter on the results (or before you search) by characters, compendium, spells, items, monsters, or forum posts, but the results are not great. For example, searching for 'darkvision' with no further filtering, I'm told there are 35 results under 'all results' - 1 character (goblins - and none of the other races that also have darkvision), 8 spells, 23 items, no forum posts, 33 monsters, and 35 results in compendium. That just doesn't work out, no matter how you run the numbers. But if you could at least exclude things from a search (either with the filter interface or even just boolean operators!) then you could search for 'darkvision' and exclude monsters, creatures, and spells, (and probably a filter for game text rather than playing rules) then an index per se would be less necessary.

I envision such implementation as--clicking on the index, scrolling to an entry, (e.g., Darkvision). The info would look like it does in the PHB with a page number for easy reference to the physical book and then a link from that index entry to the appropriate location in the non-page-numbered PHB compendium, which would be the equivalent location in the book.

I do use Google for looking up stuff on occasion, but it is annoying to have to open another app to get useful information. I'm new to D&D Beyond, but I don't think I could quickly reference stuff during a session--it would be faster to pull out my physical copy of the PHB. But I purchased D&D Beyond content and signed up for the Master Tier subscription to make things convenient and easy while DMing. I'm hoping that such features are implemented sooner rather than later.

Perhaps so. The index suggestion could be one form of search.I am just now becoming a hybrid physical copy/digital DM, so my brain was just fixed on the idea of an index, but it may as well be as easy as making a better search function. I'd be happy either way.

I think a better search is the way to go, maybe with operators. If I could such for sense:darkvision or item:longsword and limit my results, that'd be great.

Quote from Davedamon >>

I think a better search is the way to go, maybe with operators. If I could such for sense:darkvision or item:longsword and limit my results, that'd be great.

 When it comes to items, magic items, and monsters you can.