This game keeps getting updates, but the last stand-alone patch put out is for version 2.028. Recently there was a 2.49 and today 2.50, but still no patch. Do I really have to re-download the whole 2.3GB installers for every single little update?

Probably yes as a mere 2GB is considered tiny. Be glad it is not over 100GB like some games. I know very well not everyone has blazingly fast connection. If there are patches for games on GOG, they tend to be only for the previous version and if you miss that one you have to download it all as they remove the old patches when they add the new ones. Not sure if always for all games.

I don't know why it is so hard to keep the Changelog up-to-date.

It is one thing to have to re-download 2+ Gb, but another to do it for who knows what reason.

Uploading the update should go hand in hand with adding to the Changelog.
Are GOG really that strapped for time?
And if so, why doesn't the developer post in this topic, meanwhile.
Or if it is all the fault of the developer, they seriously need to get their act together.
Even if it is just a link to their site to see the details of an update.

Totally B-Grade the way things are here sometimes.

And yes, I know about the huge ongoing topic here, called - What did just update?
Or somesuch. Often devoid of any real detail, and honestly a pain to browse and so bloated.
Gotta be a better way.