The relative URLs can properly work if you are not using any subdirectories (e.g. pretty URLs), but the problems begin when you go e.g. to the tag page. The issue is quite big and needs a bigger rewrite in the rendering engine. At this moment we have no ETA for that, but we will try to bring back this feature in v.0.37 or v.0.38.
Do you appreciate the support you've received today? If so, consider donating to the Publii team by clicking here; we'll be sure to use your donation to make Publii even better!