Fermenting temps & Fermometer accuracy

This stout is my second all-grain. The first was a Maris Otter SMaSH, which has been bottled for nearly a month at ~68°. Its clarity has improved some, but not much since packaging. I didn’t use any finings in the SMaSH.
So, yeah, I'm curious about clarity. I added Whirlfloc @ 15 minutes to the stout. The hop spider left very little trub. Time from burner to 68° with immersion chiller was about 30 minutes.
If the stout has similar (non)clearing results I’d like to name the culprit. That said, I’ll set up to keep the bucket around 66° while away and see whazzup on Sunday the 28th.
FWIW, my non-Hefe extract brews have been as clear as bell.....so I keep returning to the mash as a starting point for sleuthing, if needed.

I suspect there are 3 or 4 formulas that are more or less widely used....but knowing which one is best can be confounding. A few returned the exact same results, but the spread between the high/low results seems noteworthy.

 

14 days will have elapsed from the time I pitched to when I return, so no worries there.

I'm not of that mindset; more like "when the last bubble comes out of the airlock" (or thereabout) it's time to start reading the gravity and let bottling day be determined my points instead of days.

Although I didn't ask specifically, one of my questions would be, "If fermentation completes in my absence, might there be adverse effects from it sitting on the cake for 2, 3 or "X" days?
When does sitting on the cake become detrimental? Most likely the answer is "Well, it depends...." an on we go.

 

Thanks to @PortLargo for the article on Conditioning: Fermentation's Grand Finale; very informative.

Before i left for 9 days I put the fermentor and a space heater in a small bathroom and attached the heater to an Inkbird TC-308 to maintain a temperature of 64°. The Inkbird probe was taped to the outside of the primary bucket.
Set the house thermostat to 52° as I normally do when being away.

Equipment failure:
When I got back today the heater fan was blowing and the probe temperature was 54°. The small portable heater had become a small portable air mover....heating element failed.
No idea when it failed and therefore no idea how long it’s been at 54°. It might have happened during or after the attenuative phase, which it had already entered before I left.

Cranked up the house heat, put the bucket over a floor vent. Within 15 minutes it began bubbling through the blow-off tube at a rate of about 3 per 5 seconds, and another 15 later it's ~1 per second.

I haven’t taken a gravity reading yet but can this evening and over the next couple days. Predicted FG is 1.018 per BrewCipher. BC also predicted a Post-Boil OG of 1.065, which I missed by 12 pts (1.053).


Question: should I just let it go until activity subsides and then begin taking the gravity readings? Maybe the yeast just went dormant and the newfound heat got them reinvigorated.