At the moment there is no way to avoid lenscorrection on certain lenses, and the list is growing with almost every new lens.
It
is possible to strip the embedded lens correction metadata, but
- the process is awkward;
- it requires third-party software;
- the only application I have found that works is restricted to MacOS;
- I haven't done exhaustive testing and it is possible that removing the lens corrections in this manner will break some other Lightroom functionality.
That said, first create DNG versions of your raw files with
the Adobe DNG Converter. Then process each DNG with the
McGuffog&Company DNG Cleaner application, selecting the options "Remove all opcodes" and "If a file already exists: overwrite." Finally, import the converted and correction-stripped files into Lightroom.
I've attached two JPEGs generated, respectively, from an original Fuji X-T3 raw file and a converted DNG with the lens corrections removed. The difference in geometry is apparent even in these low resolution samples.
Obviously, it would be preferable for Adobe to offer this as an option in the Lens Corrections panel. I wonder if the problem is contractual. Perhaps the camera manufacturers are sharing proprietary maker notes metadata with Adobe in return for Adobe's agreement to apply the included lens correction values as a mandatory adjustment.
From the camera manufacturer's perspective, this presumably would make the quality of the lens appear better than it actually is. Or, perhaps more accurately, make it appear better to the vast majority of users at the expense of inconveniencing the small minority who might have a specific reason for making their own geometry modifications. This is conjecture on my part, but I can't believe there is any
technical obstacle to making the application of these metadata optional.