The purging is a scan with `next()` and a `lookup()` for each item. Since the logic is a simple `<` comparison, could this be done with a single `match_delete` instead? (Unfortunately, ETS match specifications are quite wonky, so without a lot of fiddling myself, I can't suggest exactly what the comparison logic would look like, but I know that you can express certain things like comparisons with it.) That would cut down on the back-and-forth between the elixir process and the ETS process.