I agree, the UI needs to have a "hold this button to scale the window" feature, since the grab-points for scaling the window are FAR in excess of the window.
Problem: the window scale point stretches the full width/height of the screen, instead of only the width/height of the UI window.
EX: (and this is the most common variation) if a UI window has it's bottom "scaling grab" in-line with the hotbar, then one will inevitably grab the goddamn UI window instead of the hotbar.
(other variations include accidentally re-sizing the advanced build mode info-box instead of placing/removing a block on the target ship, because the top/right side of that fecking box lines up with where you clicked on your ship)
Solution:
Either fix the goddamn UI window scaling grab-points to respect the actual size of the UI window. (#1)
OR, put in a "control button" so you confirm that you actually want to scale the goddamn window, instead of grabbing an item off of the hotbar/failing to place/remove a block on your ship.
(I actually reccomend ALT, as CTRL is used by default for Adv-Build mode)
I'd link a youtube vid of this happening, but I haven't seen one actually catch this happening.
Probably because most of them edit out that sort of "mistake".
Notes
#1: I vaguely, rrepeat, vaguely recall this having been brought up before, and equally vaguely recall that poster receiving a response of "we can't fix it because reason" and the reason not making sense.