Especially given that discovery on actual day one was so poor (no categories, no charts, limited features) that anything not featured was going to struggle a bit. Our app was written up a couple of times alongside Simplex but missed out on a feature despite getting an artwork request and only had a few dozen sales.
Ideally the user would choose the time the mail gets delivered. I have to have my phone on during the night in case of emergency and there is nothing more infuriating to me than a company that sends me email in the middle of the night, causing my phone to beep and wake me up.
The author is talking about application/rate_limit_status which is also rate limited. The headers are great if you keep track of them from the response on your other calls, but if you want to see your rate limit status across all endpoints you can use: