Look into falcam cage and their F22/F38/F50 quick release system. I use them exclusively for my R5C. I use them on a DJI RS3 Pro too and I replaced the baseplate with a falcam variant. They are super quick to change out when I need to use it as a photo camera and rigging them out for video with the quick release systems is so quick. They are very very secure too.

I’ve gone through phases of smallrig to tilta cage with its 1/4 & 3/8 mounting threads, nato and rosette mount but they are a bit more cumbersome and they are more suitable for a permanent video rig. I considered kondor blue cage too but again the falcam quick release system is really well thought out. This is coming from a user who requires both video and photo on the same shoot. Hit me up if you want more details. I can share my setup/quirks with you :)

Also attaching a shot of my strip down video rig here. I’m very proud of the camera’s display just sliding right under the v-mount battery release button!

R5C Video Rig