Can I Swap Out HD Clips For 4K Clips From Within A Multicam Clip?

I recorded a 5-camera interview with externally recorded audio two ways.The first way is that each of the five camera angles recorded 4K internally along with an audio mono mix hopped from the sound mixer. Each camera also has embedded timecode.The second way I recorded video and audio was to an Atomos Sumo recorder via 4 SDI inputs from 4 of the 5 cameras and we also fed timecode into the Sumo so each camera iso recording has embedded timecode. We did a live cut between camera angles on the Sumo which also saved a 5th recording of the live edit along with a multi-cam XML file for FCPX.My idea was to tweak the Sumo's multi-cam HD recording to quickly turnaround a first cut, apply the requested edits to the HD version and then go into the multi-cam clip and swap the HD files recorded by the Sumo with the 4K files recorded in camera.I would also add the higher quality externally recorded audio and make it the monitored audio.While this initially seemed to work, I quickly noticed that:1. The parent multicam clip names didn't change even though I had appended 4K to their lane name in child clips.2. The added audio isn't present in the parent clip and the audio that is present is from the original audio role before I disabled the audio monitoring and added the new externally recorded audio and make it the monitor source .It is as if the parent clip is still referencing a previous version of the multicam clip.If anyone have any ideas on how I could get this to work it will be very appreciated.