So I'm excited to start using the Asset Library, though I am disappointed at how it handles pivot points. Since it always uses the center point of the model, iterating between different models with the 'replace' feature is messy. I have recorded a short video illustrating the problem.
It is my understanding that it's current design is intentional, according to this developer response, but I would urge you to consider giving the user control of where an object's "base" is:
https://apps.autodesk.com/3DSMAX/en/Detail/Index?id=6015429456303731618&appLang=en&os=Win64
" As far as the pivot, we started with the center as we ultimately weren't sure which type of content our users would be dragging in. Would it be full scenes, or single assets? Would they need to be placed on a floor, ceiling, wall, etc.? We thought the best approach in all those situations would be to start from the center."