hi! there are no plans to support more engines for docx. the complexity there is already high, we don't want to complicate it more.
What makes using handlebars tricky for us is inability to address results of the function like
getData(this.order).name
I understand that by handlebars ideas data should be prepared beforehand, but it really overcomplicates things for us.
not sure if you are aware but, handlebars supports subexpressions, which will simplify your calls to this {{lookup (getData order) "name"}} (the lookup helper is a handlebars builtin helper FYI)