If the intention is to find help, then you will need to provide details about your configuration and installation, at present there is little to go on - no logs, no charts (previously requested), no photos.
If the purpose is just to rant, then there is little this community can do with that - we aren’t a support site, nor is this an ask Victron space, so it’s just ranting at a group of volunteers and enthusiasts who try to help, which won’t encourage much engagement.
If you need formal support, the support link is in our guidelines.
These systems are successfully installed in confined areas and mobile and marine applications, so if you want to get to the bottom of the issue help us to help you and try leave the frustration at the door on the way in.
As already shared, the image of inverter temp derating has zero to do with the GX controller, it in no way applies to that specific device’s operational envelope.