Access settings from Window -> Voxel Busters -> Cross Platform Replay Kit -> Setting menu.
Video Max Quality - Set max quality you want to allow for recording the video on Android QUALITY_1080P - Video will be recorded at 1080p max resolution if the device supports. QUALITY_720P - Video will be recorded at 720p max resolution if the device supports. QUALITY_480P - Video will be recorded at 480p max resolution if the device supports.
Custom Video Bitrate - Enable this if you want to setup custom video bitrates. Usually default bitrates on Android for video recording uses higher bitrates leading to good quality but bigger file sizes. This setting allows you to choose from optimal recommended settings and choose a factor between min and max values.
This will give a better file size without compromising much for the quality. Choosing the factor is based on the content length you may record in your game.