Multicam project bloat

I'm editing a multicam with only 2 sources :
- A Sony HDV (1080i50)
- A JVC XDCAM EX (1080i50)

FCPX does not allow me to optimize my media, so I only created proxy media.

The project duration is 1H20.

The creation of multiclip is done smoothly, for audio I have 4 different sources that I have not included in the multiclip but in my project in order to mix them.

I made a first "draft" color-correction directly into the multiclip in order to have a better visualisation during editing.
Maybe a little too much ? Two corrections per clip, with sometimes fades between clips for smoothing CC transitions. (So, ​​cuts in the angle editor, and fades)

At first everything was fluid, but the more I advance in the edit, ie the higher the number of cuts increases, the more my project severely slows down. To the point of having to wait 10-20s for each angle change.

The size of my CurrentVersion.fcpproject file is 300 MB!
The initial project without edits is only 10MB

I tried to split my project into 4 parts, but it changed nothing. The third part alone is 280 MB.
Also tried to disable my color corrections, nothing.
The switch to proxy playback does not solve anything either.
The project still plays fine, it bloats when I try to change angle.

So, I'm a bit stuck ...

Apparently there were some bugs in the record on the XDCam camera . FCPX refused to convert two clips into proxy. I found passages that were a problem (sort of digital drop / green image that crashed fcpx) and have removed them from the project to insert the source footage from the other camera instead.

I also used a compressor on each of my four audio sources, but disabling it does not help either.

Rendering in the background is disabled,also are the reference audio waveforms.

I tried to delete render files, preferences files with preferences manager, empty FCPX caches, then fixed permissions.

I also tried to copy-paste my project, and only a part of it, in a new one. No success either...

I'm running fcpx 10.0.4 on an i7 Imac with 16GB of RAM, and my HD consists of a mini tower with two disks in RAID 0, connected by FW800.


Does somebody have an idea ?

The JVC Cam apparently had recording issues.
But I need this shots to complete the edit.
Anyway I copied the multiclip then restarted a new project with this new copy.
It seems ok for now...

Do your Color Correction after you make your edits. I ran into this issue on a 2 hour recital. The more edits you make the slower the project became. I had made Color Corrections before editing. My next wedding about 90 min with 4 different multicams I did Color Correction at the end and my work flow was way faster.

Thanks for your answer