Can I safely reduce the height of this tub stopper?

Question

Re-doing a bathroom, original plumbing c. 1963. That tall silver thing stops the tub. You lift and turn it to stop water from flowing out. As you can probably guess, the stopper is preventing us from putting our desired vanity in.

Questions!

• What is the name of that thing, so I can research it further?
• Does it have to be that high? One solution is simply to reduce the height. I can't think of why it would need to be that high, but I also don't totally understand the mechanism underneath.
• Do we need to get a plumber involved to reduce the height, or is this something that our contractor should be able to tackle?

Answer 1

It's a tower drain, aka standing waste, and you can't make it shorter without limiting the water level in the tub, since it's also the overflow for the tub. Looks like there's already a pretty good description of them at

How does an external tower style bathtub drain work?

Answer 2

Why not use a pedestal lavatory and use a movable cabinet for storage? The tile is interesting and I wouldn't want to cover it up with a vanity. I wish I had put in a pedestal lavatory in our bathroom when we re-did it 20 years ago. It's more flexible and allows change without tearing things out.