TIL that copying an assembler to a requester chest sets it up to request ingredients for the assembler.

Here's the behaviour: shift+right-click an assembler which is set up to make something, then shift+left-click a requester chest. Then the requester chest will be set to request twice the amount needed of each ingredient needed. For example, if the assembler is set up to make a speed module, the requester chest will request ten circuits and ten advanced circuits. Interestingly, the multiple seems to vary depending on the recipe - for example, for gears it'll request twenty iron plates.

I wish I'd known that before I'd set up logistics-based assemblers for about twenty different items, but I know now!