R3 has an automated tiler which allows you to add new terrains that every user of R3 across all unit websites will immediately and automatically benefit from.
Follow instructions here to add support for a new terrain.
R3 has an automated vehicle icon colourizer which allows you to upload new vehicle icons that every user of R3 across all unit websites will immediately and automatically benefit from.
Follow instructions here to add new vehicle icons.
Please file an issue on the R3 GitHub
If you'd prefer to chat to the developer look for Titan in the ACE Slack.