Yes, and The code is pretty self-explanatory.

If you’re interested in looking further:

Kobo’s current privacy policy says it collects reading-related usage information, including how often and for how long you consume digital content, as well as the genres, authors, and subjects you read.

Kobo’s Terms of Use contain a particularly relevant event explicitly called “Sideload,” which is described as occurring “when a user sideloads an EPUB.” So Kobo’s software does have telemetry associated with the act of sideloading.

If you are willing to keeping it offline and sideloading everything with calibre, why not use an open source one instead?

what’s the point of what? Yes you can turn off wifi to keep them from collecting telemetry, but that’s not an ideal solution.

https://literature.cafe/post/35302198/21661156

I guess it depends on how much you value your own right to privacy. If you don’t mind being deprived of it, then sure, it’s not important.

The code is pretty self-explanatory.

If you’re interested in looking further:

Kobo’s current privacy policy says it collects reading-related usage information, including how often and for how long you consume digital content, as well as the genres, authors, and subjects you read.

Kobo’s Terms of Use contain a particularly relevant event explicitly called “Sideload,” which is described as occurring “when a user sideloads an EPUB.” So Kobo’s software does have telemetry associated with the act of sideloading.