Easy way to find out how far you can build, is by going into build mode, to then start walking until it changes the menu to exocraft/item placement. This happens just after 150u (153/154) or so.
Fun fact, when my ship is on ground, the left Control Panel in the ship shows 45u. In the video it shows 1,995u all the way up on my landing pad. I guess this results in a height difference of 1,950u, which seems about right.