What is a "kitchen sink approach"?
Kitchen sink approach is an allusion to the expression everything but the kitchen sink:-
- everything that can be conceived of [Collins English Dictionary via the Free Dictionary]
In this case, it means every imaginable feature has been included.
The new CMS product has considered the furthest function that its user can imagine. Refer to 'Kitchen sink' as the final item imaginable on any extensive list of usually disparate items.
It sounds applicable in the context.