I see. We may have run into a terminology issue with this. My apologies for any confusion.
In zwave, “reset” and “exclude” are two different things
In a Z wave context, a “reset” means to reset the feature parameters stored in the device to their original factory settings. An “exclude” means to remove the information from the device about the network that it belongs to. They are two different things.
This matters because, unlike zigbee devices, a zwave device doesn’t have a permanent network ID. Instead, the Z wave controller (in this case, the smartthings hub) assigned a network ID to each new device at the time that it joined the network. Once this network ID has been assigned, it cannot be changed as long as the device remains on the network. The only way to give the device a different network ID is to exclude it from the network and then include it again.
A zwave device cannot be “included” into a network if it Already has a network ID, because it will believe that it belongs to a different network. The factory reset does not change the network ID, because if it did, there would be no way to change the optional parameters like how quickly A switch dims up or down, Or whether the LED indicator light comes on when the switch is “on” or “off,” because once the network ID is lost, the switch and the hub won’t talk to each other except for the specific command to exclude or included.
So it’s not the reset that allows you to include the device again. It’s the exclude. Because it’s only the exclude which removes the old network ID from the switch’s memory. An a zwave context, a “reset“ specifically does not clear the network ID.
Of course you always run into some translations of instructions which may use words which should have been reserved for specific Z wave meanings. Sometimes you’re lucky to get an English translation at all! 
Newer GE switches allow you to reset without excluding
The newer GE switches allow you to do the factory reset of the optional parameters with just a tap pattern. The older GE switches require you to do an exclusion Which, in the case of those particular models, also does the full factory reset. And then you have to re-include it to get it back on the network.
This is one of the reasons that model numbers matter. In the case of the switch model that you have, yes, you have to do an exclude (which in the case of those models includes the factory reset), And then the include, and that resets the parameters.
And again, in the case of the specific switch model that you have, you may have to use the airgap step as well.
As soon as I did, it excluded instantly. If anyone is maintaining a list of things to try in this situation, making sure that one is trying to exclude from the master and not an add-on would be a great addition to the list.