Another question I've been thinking about for the last... years?

Every time I connect to HH, TF2 downloads some files, which takes about 5 seconds. After the first hundred times I stopped caring but I remember trying to guess why were the files downloaded every time instead of stored locally like with other servers.

The HH pinboard that you see in spawn rooms has to be updated as the info on it is updated. But since it is a static image and not a dynamic one that we can update on the fly the image has to be updated by downloading an entirely new version, hence a new version is downloaded every time you connect/change map. It also has to be a new image since the source netcode/downloader doesn't checksum the image for differences and so if it didn't download a new version every map it would never update.

Ok. As long as it's on purpose.

I was worried some configuration on my side was not allowing the saving of those files, thus forcing a redownload, thus overcharging the server and creating lagspikes every time I joined.