Allow disabling of bucket validation

In our organization we use S3 bucket names with : (such as s3://domain:bucket/path/file.txt) which come from our Ceph system. If we try to use s3fs with such a bucket name we get an error:

botocore.exceptions.ParamValidationError: Parameter validation failed:
Invalid bucket name "rubin:rubinobs-lfa-cp": Bucket name must match the regex "^[a-zA-Z0-9.\-_]{1,255}$" or be an ARN matching the regex "^arn:(aws).*:(s3|s3-object-lambda):[a-z\-0-9]*:[0-9]{12}:accesspoint[/:][a-zA-Z0-9\-.]{1,63}$|^arn:(aws).*:s3-outposts:[a-z\-0-9]+:[0-9]{12}:outpost[/:][a-zA-Z0-9\-]{1,63}[/:]accesspoint[/:][a-zA-Z0-9\-]{1,63}$"

with botocore we disable validation using:

>>> from botocore.handlers import validate_bucket_name
>>> client.meta.events.unregister("before-parameter-build.s3", validate_bucket_name)

And this works if I use s3._s3 to access the S3FileSystem object's internal boto client object.

Is there a way to do this without having to use an internal property?

Start at S3FileSystem and trace how its internal _s3 botocore client is created, including where validate_bucket_name is registered. Done means a supported public option can disable bucket validation for colon-containing names while keeping current validation as the default; check the project's relevant tests for coverage.