Whenever I open the icon editor it always shifts position on the screen a bit vertically after a few hundred milliseconds. I took a look at the code and made the following small modification, simply calling the FP.Centre method before doing the init of the data.
I really think its a great idea this is "open source" as now the community can hopefully add lots of new features. Kudos to NI for allowing this (its the first small steps to having the whole of LV open source!).