if nothing is sticking to that spot and it isn't otherwise bothering you i'd just keep on using it.
otherwise you can scrub that area back to the metal and then make sure it is clean and dry before applying some oil to it and then using it. eventually it may even out no matter what.
i never want to heat a pan up to where an oil reaches the smoke point. it doesn't smell very good and it doesn't usually taste all that great either. once in a while it does happen but i don't do it on purpose. ooops.
one way to add more black carbon to the seasoning on the pan is to cook some sugary bbq type sauces on some bacon or ham. that will often give you some nice black carbon and oil to work with. still, i don't really worry about it too much, just keep using it when i need it.
i did check out the website and there's a discrepancy between what they post in the seasoning temperature for one page and another (one says 450 - 550F another says 350 - 450F) so that's not a good thing IMO. but to me to simply state a temperature range without taking into account the smoke point of the oil used is just blah...
and yes, others can do what they like, as i said before i'm not really too wrapped up into this, the not wanting to get to the smoke point is just my own desire not to set off the smoke detectors or to smell burning oils inside the house and not liking the taste or smells when that happens. personal preferences.