VTDecoderXPCservice taking up too much space on Final Cut Pro

[Loaded] com.google.keystone.agent.plist (Google LLC - installed 2022-04-13)
  [Loaded] com.google.keystone.xpcservice.plist (Google LLC - installed 2022-04-13)
  [Loaded] com.macpaw.CleanMyMac4.Updater.plist (MacPaw Inc. - installed 2022-02-02)

User Login Items:
  [Not Loaded] CCC Dashboard (Bombich Software, Inc. - installed 2022-03-28)
    Modern Login Item
    /Applications/Carbon Copy Cloner.app/Contents/Library/LoginItems/CCC Dashboard.app

  [Not Loaded] CleanMyMac X Menu (MacPaw Inc. - installed 2022-08-12)

You have both Chrome and CleanMyMac installed. At a minimum both Chrome and CMM need to be completely uninstalled. You should then download a new copy of FCP. Because of CMM it's likely you might need to do a clean install of the system.

There is no need to do different versions of the report.

One thing that, as I suspected, stands out:

you have Chrome and its keystone daemons.

User Launch Agents:

[Loaded] com.google.keystone.agent.plist (Google LLC - installed 2022-04-19)

[Loaded] com.google.keystone.xpcservice.plist (Google LLC - installed 2022-04-19)

Any time we see VTDecoderXPCservice using a lot of resources we suspect Chrome, and we are usually right.

See https://chromeisbad.com for an explanation of what these do, and how to completely remove them.

Afterwards, you will need to delete FCP and download a fresh copy from the App Store.

Chrome's software is still installed.

User Launch Agents:
[Loaded] com.google.keystone.agent.plist (Google LLC - installed 2022-04-19)
[Loaded] com.google.keystone.xpcservice.plist (Google LLC - installed 2022-04-19)

Follow the instructions at https://chromeisbad.com and once everything has been deleted and you've rebooted, drag FCP to the trash and download a fresh copy from the App Store.

Please post an EtreCheck report https://etrecheck.com giving the application Full Disk Access in Privacy System Preferences. Copy the report and use the Add Text button to paste the result into reply box. 

its frustrating... I found workaround , it is to play the timeline when the process goes really high, just the time to clean the memory and I stop the play so it can finish. For me it's only way I have to export a long video

Please post an EtreCheck report https://etrecheck.com giving the application Full Disk Access in Privacy System Preferences. Copy the report and use the Add Text button to paste the result into reply box. 

Shut down your other computer (because the first one you posted about is hosed). Disconnect all external devices. Boot the computer with the latest EtreCheck report. Create a new admin user. Log into the new user. Launch FCP. Create a new library. Import a few clips. Put them into a project without doing anything else and export a master file to ProRes. What happens step by step?

Is this the most recent Promise RAID driver? Are you using a Promise RAID?

 /System/Library/Extensions
    [Loaded] PromiseSTEX.kext - com.promise.driver.stex (6.2.13 - SDK 10.12)

Could the high XPCServices usage be from Safari/WebKit?

 2022-07-28 16:26:32 com.apple.WebKit.WebContent High CPU Use (3 times)
    Executable: /System/Library/Frameworks/WebKit.framework/Versions/A/XPCServices/com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent

That is not an issue. Please see the new report from my other computer. I just plugged in the external drive and tried to export the project. The same problem with VTDecoderXPCservice (eats all memory and crushing).

Have the same problem. It isn't connected with chrome. I never installed it on the system.

Once I solved it trying to disconnect the external monitor, but with the software update got this again.

The latest driver available.

I can completely close safari and the problem stays.