As any dwarf engineer knows, all activable mechanisms must have some sort of a trigger - be it manual dwarf labor for lever pulling or creature/minecart/liquid presence for pressure plates. However, these dwarves probably don't know they are in the computer game containing various bugs, glitches and exploits, and sometimes player can directly affect in-game mechanics without any help from fellow dwarves. By "directly affect" I mean everything that does not include giving orders or placing designations and affects not only dwarves, but other creatures, terrain and environment. Two examples I know of: player can lock a door (for example, to force sieges without building destroyers to change their route) or cancel a suspended construction with some materials "in it" to force their immediate drop as items. Both these actions affect other creatures/environment without any dwarven assistance. So I hope there is such an action which can result in reliably triggering mechanisms akin to pulling levers and pressing pressure plates without dependency on creatures AI's and their pathfinding (aside from DFHack's
Initially the idea was to designate constructed wall above a pressure plate, let a dwarf start building it and suspend the construction before it was done, thus creating an improvised stone trap ready to drop it's boulder on cancellation. Hovewer, turns out only liquids and creatures trigger pressure plates, not items. Then I thought to place a fragile non-grazing disposable creature on the plate so the boulder would smash it and thus halt the signal, but even heavy falling boulders do not give 100% guarantee of such "smashing" - thus, no reliability (also, the said creature must be replaced after each "activation", but it's not the main concern).
So... well, I'm stalling. Any advices (or even better, a solution) will be greatly appreciated. Thanks in advance!