A few (scattered) thoughts.
1) I've never made much use of it myself, tbh. I generally find my shipyard space is more abundant than my factory space. But then, I'm a relative newbie who hasn't gotten all that deep into the game before.
2) It seems odd to me that they're a way of moving production from a shipyard into a construction factory. On principle, shipyard-made components appeal to me more than factory-made, but I can't think of any way to balance a shipyard producing components instead (it'd sort of make a mockery of the size limits in practice).
3) I like the idea of using components to speed up production, if only because it's a worthwhile usage for salvaged/scrapped ships. I don't know if there's a reasonable way to do this without just keeping the current system, though.
4) For salvaging alien wrecks, "blueprints" work just fine. To avoid the headache of needing to move it around (or to share research), maybe make it something like a 50% cost reduction to the appropriate tech, perhaps.
5) I see why people say "throw it in, people can just choose not to use it", but that seems to ignore the cost of you needing to code it in. If it's a ten-minute job then fine, but if it's a bigger feature(which I assume it is, if it hasn't been done in the years you've been working on this), then it doesn't strike me as a high priority. Perhaps add it in a later version, if that's the main reason.