Earlier quoted context omitted.
We don't do anything automatic like that (yet?), you will have to add indexes manually. But I would have to say - modern day databases are so fast that you probably won't notice the performance of adding indexes until at least 100k+ rows in a table and/or you have very high read throughput on that particular table.
You'll see a performance benefit way before 100k rows depending on the size of each row, especially with sorting. It might save you guys a ton of CPU hosting wise, depending on how this all works, to track slow queries and auto add indexes. Way worth the write overhead in most cases.
It’s likely that most of their customers would only have a few hundred or thousand rows where indexing may not actually matter after all. Otherwise I’m sure they would’ve prioritized it.