Most Wikipedias have very few technically-inclined editors, and are therefore unable to write citation templates or enable them for the visual editor. Enabling citoid for them might be a mitzvah for those communities.
The simplest route would probably be importing templates from the English Wikipedia (or perhaps from the nearest fallback language). This would result in the templates being in the 'wrong' language, but this is unlikely to affect most users of the visual editor (who will use the citoid service instead of the template editor), and it might encourage more citations, less linkrot, and better reliability.
# Find the citation templates used by the [VE Citation tool](https://www.mediawiki.org/wiki/VisualEditor/Citation_tool)
## If the VE Citation tool is not installed, first inquire at the Village Pump. Some communities do not want to use templates.
## Import basic 5 templates from en wiki (import requires sysop privileges).
## Enable Visual Editor Citation tool
# Write TemplateData for each template in the citation tool.
# Write the JSON maps in the TemplateData that citoid needs to find and use the citation templates listed in step 5.
# Enable the VE citation tool (non-citoid citation feature) (requires sysop privileges).
# Install the JSON Mediawiki message that turns on citoid (requires sysop privileges).
 ja - not requested; should we ask the community before enabling it?
 hr - requested here