Please feel free to open a new feature request, if the feature is not already described by one. it is very unlikely that any new feature will move into 3.0 or 2.5 that is not already in as 2.5 will be released in the first week of December and 3.0 on the 14th Feb. 2019
We canβt give any warrenty that any Plugin that was written for Graylog 2.x will work with 3.x. The creator of the Plugin might need to adjust something.