I used Zotero quite a bit in the past, the thing that ultimately drove me away is that when synchronizing you couldn't easily access the PDFs just via the filesystem. I use a nextcloud and also wanted to access PDFs from devices without Zotero installed and this turned out to be a pain at the time. Is this possible with more recent Zotero versions? Is the sync still cumbersome with a zotero account + self-hosted webdav?