Regarding full width, it is a bug introduced by new versions of Logseq, the plugin is supposed to work by exporting whatever you see in screen the way they are. I fixed it in the newest version.
Custom CSS is possible by just overriding in custom.css. Say you want the tags be shown:
hey, thank you the the very useful plugin ! Would you consider adding these settings
show/hide tags - currently all tags seem to be hidden with
use the full width (or follow logseq's current mode)
add custom css rules (I mean adding specific css rules for doc export, on top of the custom.css), this could solve the 2 issues mentioned above