I do take your point - to an extent.
I think the subject you're touching on is basically that of configuration. Configuration is what allows you to change the behaviour of code without making a code change. Configuration is of course very really powerful for good and evil. Someone below mentions ODBC which, yes, 100% is a great example. But the one that sticks in my mind is resolv.conf.
I would contend (:)) that csvbase-client is not doing "fiddly magic at package installation time" but supplying configuration for a url scheme. In much the same way that installing boto3 does for using the `s3://` url scheme.
"Magic" in my book would be monkeypatching the methods of other libs. I would hate to write `csvbase_patch` and have it execute on the import of a specific module. Like you, I prefer to live in a low-magic fantasy world.