To the last point - Because some people already obtained those items (before they were added as collection logs) and may have them in their banks or PoH, why not let them use the Collector to get the clogger of something they've already grinded?
Then they should have to re-grind it just like every other game mode has to do, or like to my original suggestion, stop adding misc. collection logs after the content has been out for years.
As for the Spirit shields from Bloody keys.. not sure how to deal with that, but people already get some collection logs from voteshops or other ways that aren't the actual grind of the meant monster/drop, so i don't see the big issue since at the end of the day, not that many irons are opening hundreds or thousands of bloody keys to get a spirit shield sigil.
Arcane was merely one example, there are many items that could fall under this, the onix from tekton, SOD/magic fang from bloody chest, ....
Just my opinion but there aren't many multi-year old ironmen who had items before the collection log came out like there are in OSRS, this suggestion just seems like it would be taking time away from working on content like Huey, Doom of Mokhaiotl, fixing other stuff ingame.