grrrr, Thank you Alin.
for some reason, I have always thought that "gap control" meant that it is going to CLOSE the gaps at or under a set condition.
What is used for then? Anyway. As always, this group got me back on track in a fraction of the time I was wasting on trying to find my own solution. Many many thanks to all that contribute.
Yes it should, my guess is considering the reason it was put in was because SolidWorks was knitting edges to about 1mm by default, and that was too large for some models so you would collapse down more edges than you would like.
Hence by turning on gap control it makes that tolerance finer and then presents options to you, you should have gotten some checkboxes with tolerance values next to them in the gap control, if you check those on it should also knit and allow you to thicken.
I am unsure whether you can edit the feature and get those values back, you may need to delete this knit and use a new one. Should you wish to try it.