It looks like this could be quite a handy tool if you’re stuck with an issue that can’t coexist with the latest version of WordPress.
WP Downgrade | Specific Core Version has the potential for becoming one of the best-loved plugins among those, who simply cannot update to the latest WP release.
In the past the latest WP release was the only offering for WP’s Automatic Update routine. This left all those behind, who have to wait with Core updates, until their plugins become compatible with newer WP releases. When this finally happens, more often than not there has already been yet another Core update. In the end a dreaded, cumbersome, time-consuming and error-prone Manual Update used to be the only way to go.
With WP Downgrade | Specific Core Version this is now a thing of the past. Anyone who lags behind the latest WP release is now able to use Automatic Updates even to lower WP versions. What WP Downgrade does simply is to make WP believe that the version you want to update to actually is the latest version. Because of this, there is no difference to updating to the latest version.
For security reasons I think this is a must-have plugin for anyone running a “seasoned” WP installation, and it actually should be a Core feature to be able to update not to the latest WP release exclusively but instead to have a choice among secure releases.