Does that mean you would be fine to give up all the holdings you have in the old kingdom if you are allowed to create the new one?
In CKI I always tried to get rid of the lands I had in Europe after I had created Kingdom of Jerusalem, because I really didn't have time for Boulogne and Lower Lorraine when I was trying to build my empire in Levant, so I usually gave my European provinces and titles to relatives and didn't react when they declared independence because of distance. Besides if King of Germany or France would have wanted to take those lands it would have been practically impossible and far too expensive to defend those territories. If I manage to do the same in CKII I assume France and HRE are going to be even more pain in the bottom if I try to keep those lands.