when downloading the "HOURLY BUILDS" there is only a very general indication: "Download a preview of the incoming release with the most updated features and bugfixes." But is there any information on current changes like the Release Notes for the final builds?
You could always check the Github repos to see what is happening.
But I agree a quick overview would be nice.
They do update the release notes with major changes:
This file has been truncated.
ARDUINO 1.8.17 Not yet released
ARDUINO 1.8.16 2021.09.06
* Removed the very outdated off-line documentation.
* Do not crash if a malformed boards index URL is entered in preferences.
* Fixed font-resizing problem with multiple tabs open.
* Updated FTDI drivers to version 184.108.40.206
* Added latest firmwares (up to version 1.4.8) for NINA-based boards
ARDUINO 1.8.15 2021.05.13
* Fixed regression in library discovery (failing to compile bundled libs, like SD or Ethernet, on some platforms)
If you want the full list of changes, here it is:
That shows all commits since the 1.8.2 release. After each release you need to update the version in the URL.
If you want to get more complete, there are several repositories other than Arduino/arduino that are included in the Arduino IDE: