I´ve seen that Chomikuj.pl was mentioned before, but no documentation was given. It seems "Grycek" implemented a client for downloading/uploading files from/to Chomikuj.pl on python:
Would it be possible to add it? Using RClone as Chomikbox would be amazing.
No, it does not have a published API
It does not have an english website, but translators work perfectly on it
Yes, i tried the python client and worked for me for uploading files from a linux VM i have