I'm having a hard time getting a good view of how he triggers goblindumper due to the way he looked at that- and because I've removed myself from default graphics so much I can barely recognize machinery in it anymore.
Is it just pressure plates triggering a gear assembly and a pump triggering a pressure plate triggering the bridges?
*and also maybe turning itself off-
I like how effective it is but it and half of the other videos aren't really goldberg-y. The anti-goblin stuff is very efficient and just sort of an unconventional way of dealing with them rather than way too many steps for a basic task.
You could needlessly complicate something like using a well by putting it at the end of a long hall with a pressure plate that closes the way behind, drains the well, and then fills it up before they get there, as well as to another pressure switch that opens a different path out that's closed at the well end as soon as the dwarf enters it and upon exit closes the far end while opening up that original entrance.
And filling the well has all kinds of complications you could employ like having lava melt ice while the original contents of the well travel through a series of screw pumps until finally being exposed to the frigid outside where they replace the ice that was melted by the lava.
*I haven't actually played to the point where I've worked with this stuff very much so there are likely all kinds of breakdowns in my Rube Goldberg machine but I think I've still conveyed the basic idea.