Yes, I noticed the same thing about my engravers. Goblins scared of Sasquatches, all the first 4 years. Not a damn historic event in about 400 masterful engravings I read through/glanced over. After reading some item descriptions I realize the accounts could be stitched on some sock somewhere instead. VERY disappointing; at this point I've given up (ran it another 2 seasons to clean up, what with the queen arriving early spring, etc.) No sasquatches showed up for a LONG time, but sometime in year 4 one appeared on my list of kills and the engravings mysteriously stopped. Eerie.
FYI about HFS:
You can't kill demons with normal traps. You can't atomsmash them. You can't drop them into a chasm with a bridge. In other words, we are not allowed to cheapass our way through a demon fight. Period. Maybe dropping the ceiling is an exception, but you have to remember that I had to dig out a complex maze to hold them all, sacrifice 2 dwarves (would have been a kitten had time allowed), and time it right to get them. There was also a loaded ballista with extra ammo and two legendary operators surrounded by champions, elites and suited legendary miners to deal with stragglers, or the whole force should they make it through. No automatic kill/cheap trick methods work, the only non-standard ways allowed being flooding, upright spikes, and cave-ins. And all of those require a lot of planning, setup, and proper execution or they are worthless. That's why clearing the HFS within 5 years (if you can find it) is such an accomplishment. NIce idea with the goblins, btw. Damn, should have thought of that
Tips with executing non-automatic traps include utilizing recruit+dismiss: Pause, recruit a nearby working dwarf, remove his jobs, un-recruit him, and issue the Pull the Lever command. When you unpause, the nearest dwarf without a priority job will grab the Pull the Lever job; even a nearby siege operator could be temporarily removed from his machine to do this. Also, placing the lever near your normal workplace allows it to be pulled at a moment's notice without sending a dwarf into danger. I made serious mistakes with all of my lever placements in my first major successful fortress, resulting in many needless casualties before I got it right. Many players place their vital levers in dining halls, barracks, zoos, or statue gardens where someone is most likely to be hanging about with nothing to do (nobles hang out there too, and LOVE lever-pulling). Some random guy whose job I had dubbed "Unemployed" pulled mine.
Some strange things going on today as I searched for a new map and played around with some old ones. Reclaiming a fortress resulted in the Merchants, captured invader humans, and captured goblins still on the map when I abandoned it showing up again as aimless friendlies, randomly placed. Odd, eh? All those Deceased wagons were a little creepy, too. And of course the bloody corpses were strung out in the halls where they were in transit, their belongings apparently strewn about but their fresh meat and that of the still-chained corpses of their livestock apparently untouched by the local wildlife.