Elm-Handlebars is a dialect of the Handlebars templating language for Elm
If you need a new feature or found a bug, please open a new issue. I will look at it whenever i've got time.
If the issue is really important to you, then you have two options.
You can either create a PR yourself.
Or donate some money via issueHunt to increase the insentive for myself or someone else to tackle the problem for you.