Thanks for building/maintaining APRS.fi, it's a wonderful service.
Your API page mentions reaching out to you to describe how we're using the API. I maintain some open-source code that makes it easy to grab weather station data from Wunderground/MyAcurite/Weatherlink/Tempest/Ambient Weather/CWOP and forward it along to Wunderground, Windy, PWSWeather, Weathercloud, OpenWeatherMap, WindGuru, and/or CWOP.
I just updated this code today to add support for pulling in APRS (CWOP) packets from your API. I encourage each person to create an account and use their own API key, I credit you all over the documentation, but I am unable to customize my User Agent headers because of limitations of the Apps Script platform.
Each request to you that comes from any Apps Script project (mine, or any other) will have the User Agent: