"Transfer ASUS DDNS name" -- What exactly does it do?

[waffles]

I found this toggle under Administration - Restore/Save/Upload Setting and was wondering what it does.

I have (2) identical AC-87; one configured as router, the other one as AP. Occasionally, I switch them around, e.g. to test different f/w or settings.

Since I use ASUS's DDNS service I always have to change the DDNS host name first on the current router, so the name will be available when I activate the other one.
I wonder if by checking this toggle, I no longer have to do this. Any pointers would be greatly appreciated!

 

[tallytr]

Is that for when you get a new router and want to keep the same DDNS name?
I replaced my router and noticed that I couldn't register the previous Asus DDNS name in the new router so had to start over with a new DDNS...

 

[primitivo]

Anyone care to explain how is it supposed to work?