No idea how well it used to work myself, I have only been using Unreal for about 4 months now.
Autocomplete did actually “work” for me initially, but was horrendously slow and the results came in batches. It was a good 5 - 10 seconds before I got anything, and after another 5 - 10 some more results would pop in, and so on. Seemed like it was scanning in real time and giving partial results as it crawled up inheritence hierarchies, rather than indexing, except that it clearly wasn’t (very little disk activity or CPU usage while it was happening).
I messed around with things a bit but never got it working well and eventually gave up and enabled the tag parser. I haven’t had to drop down to C++ many times yet so it hasn’t been significant bother; and was planning to just get Rider when it did become a bother.
If you do get it working well, please let me know! 