vertical clamping / machining angles

I'm still reading the books and watching videos to learn before even using my D840 as I want to have at least a basic grasp of what I am doing first.
But all this input gives me some wild ideas for possible projects.

for instance has anyone made some sort of rig to clamp an object vertically? I guess you would have to modify the bed so the object can pass through.
Think of engraving a bowl for instance, that has a larger diameter than the machine's Z height.

or an even crazier idea is it possible to use an attachment to engrave/cut at an angle. for instance the dremel has a 90° angle attachment.
That could theoretically be used to engrave that same large bowl if it was mounted upside down to the (unmodified) machine bed.

Now don't worry I'm not trying out these ideas any time soon, just some thought that popped into my head, were I thought, wouldn't it be cool if you could do this...