What kind of tweening do you mean, using the MOVE transition for characters or tweening inside a call action?
If the example you're referring to is the MOVE transition:
- show deuzi: WITH CUT AT OUTRIGHT - show deuzi: WITH MOVE AT CENTER
It's working fine integrated with the quickstart, something that could be happening is that for some reason it doesn't find the named positions, these are present in the Defaults.js file, under the positions key: https://gitlab.com/lunafromthemoon/RenJSQuickstart/blob/master/RenJS/Defaults.js
Check if you have the correct positions and let me know