Yes, I am sure what I use. Onsen + VueJS from my own template.
I use VueJS “old way” - no webpack, no ES6 (2015) JS code, no single file (.vue) components.
In my case everything works fine.
There is no implicit monaca template in monaca cloud ide combinatied OnsenUI + VueJS.
I have (and use!) my own template for monaca ide - OnsenUI 2.x + VueJS 2.x
So, I have the request: please add templates (OnsenUI + VueJS).