Not only do they have customer service if things go wrong, they have customer service to take random requests.

I've submitted four "hi this is just a feature request, no action needed" tickets to FastMail over the four years I've been a customer. Every time, a person who appeared to have a clue (based on their responses) replied to me with at least confirmation of "sure, we'll think about it, might be a heavy lift" and they did two of them.