There's always little problems here and there to fix occasionally. Its part of the fun and to take you out of your comfort zone.

the iron trick may be your only option as its a quilted veneer that is VERY thin. do not attempt to sand it out. if its still there after swelling you may get away with timber filling depending on the filler you use and the type of stain and colour you use. In Australia we use a waterbased filler called timbermate. I've had some brilliant success with patching with timbermate and staining the wood and timbermate black. almost cant see the patch. Not sure if that would work with a quilted top.

Alternatively, if a ding is still there after swelling, you could go ahead and stain and fill the dings in with the clear coats. you will just need to put more on than usual.