This is high experimental as it is not yet well tested. Basically this update adds an encoder plugin to OBS. That means you can make use of GStreamer supported H.264 encoders for streaming and recording.
Upon loading the plugin queries installed video encoders - so supported codecs depend on your system and GStreamer installation.
Currently available are x264, NVENC, OpenMAX (Tegra), OpenMAX (RaspberryPi), VA-API and VTENC (Apple hardware). Some of them are available as native encoders in OBS itself and there is little point in using them in this plugin rather than in OBS directly. Others may be helpful when porting OBS to different platforms - then this if for you.
Again, this is highly experimental. If something does not work for you, check if the x264 one of this plugin is working and report your issues. We just have to fix this together as I probably lack the hardware to make tests.