.PART files - not removed (S3 attached storage)

I’m using S3 storaged attached to Nextcloud 18.0.3 (yes, I’m aware there’s a newer version, but my users are currently relying on it), and I’ve noticed that the hard drive is filling up with .part files. The log file is also occasionalyl stumbling on “filesize(): stat failed” errors specifically on these files.

Is there any harm in removing them to clear space, assuming the files have been successfully transferred? What are some possible things I can try to stop these errors from occuring? Thanks.