Failed to Share Custom Format Project - Error Code Guide?

TROUBLESHOOTING SHARING FROM FCPX 10.8.1

I am having sharing issues. (It's not that I don't want to share). I am trying to share a short file of 9-minutes, however it is a complex 8K project with a custom frame size with 2 screen areas imbedded in a single custom frame format as well as multi-image sequences and a variety of media. 

I have had some success with export including some output at full final resolution, however more often than not of late, it fails to share even at 4K. Unfortunately, the error numbers and messages and apparent fail points vary from fail to fail. I have also had red "Missing Plugins"populate the project at some points although these seem to come and go without my being able to find an explanation. I don’t know that I am missing a plugin. 

Details. MacBook Pro M1 Max; 32GB memory running OS X 14 and just now, 15.1. FCPX 10.8.1. The main high-resolution camera media is 8192x3420 Canon Cinema RAW Light at 59.94fps. The custom frame size for the project is: 7748 x 3569. There is masking and countermasking within the frame to separate the scenes/clips for two different screens.

It could of course be that the processor is not up to the demands of the project complexity, which includes retiming from 59.94 to 60fps. 

I have tried simplifying some compound clip constructions, eliminating any Optical Flow requirements (frame rate changes are all now using good frame blending). 

HOWEVER, WHAT WOULD HELP ME WOULD BE TO UNDERSTAND SOME OF THE ERROR MESSAGES, OR BE ABLE TO LOOK THEM UP.

I am trying to assess whether a hardware upgrade will help or whether the project needs to be disassembled into smaller chunks (shorter timeline segments, but also sliced down from its stacked double screen compound frame format into respective screens. All of these changes involve some considerable work and complexity. 

Thank you for any assistance or insights you can provide.