Fermentation Temperature Control

I have a fridge that I have an Inkbird temperature controller hooked up to. I am curious if someone has an idea of if I should keep my temperatures in a short 4-6 degree range or should I set my temp controller to kick on and off at the temperature the manufacturer says is the optimal range for the yeast I’m using. For instance, I’m currently fermenting a sweet stout. I pitched Nottingham yeast. The range per the manufacturer is 57-70f. Currently I have my set up to kick on at 68F and kick off at 61F. Should I change this to kick on at 70F and kick off at 57F or set it even a different way?

Keep it in the short range. Large temperature swings may stress the yeast. You have the temperature probe attached and insulated on the side of the fermentor?

I pushed the fermenter in the corner of the fridge and put the thermometer in the center behind the carboy. Hopefully that gives me a close reading to wort/beer temp.

I pushed the fermenter in the corner of the fridge and put the thermometer in the center behind the carboy. Hopefully that gives me a close reading to wort/beer temp.[/quote]

You will still be controlling the ambient temperature of the refrigerator. The probe should be taped to the side of the fermentor, and then insulation placed over it so it is not affected by the ambient air temperature. I am using a piece of foam mattress pad. Conforms to the shape of the probe and is easy to tape on and remove.

Ditto on all the info above. Yeast behaves differently at different temps, so pick a single temp and try to stick to. (I have all my inkbirds set to ±0.1 degree)
At the higher end of the recommended temp range, you’ll be getting faster fermentation, but more esters and flavors of stressed yeast. At the low end of the range you’ll have a much cleaner, subdued yeast characteristic, but slower fermentation. I typically choose a temp right in the middle of the range.
A good practice is to begin fermentation at the low range, and then bump the temp up after the beer is mostly attenuated. This keeps your yeast in the low temps initially, when they are most prone to creating off flavors, but then gives them a temperature boost to increase their activity and help reach full attenuation.
For instance, with Nottingham I would probably have the temp at 63F for the first few days, until airlock activity calms down, and then would bump it up to 68F for a couple days until airlock activity ceases, or I reach my desired final gravity.