Though this is not documented, the contents of the Leftovers nodelet is managed by the SiteDocClan, so in the future you can ask them about such changes instead of invoking the gods.
Update: no, I won't do the edit myself. I still think the Leftovers should be split to two nodelets, one containing links to the Perlmonks infrastructure nodes that don't have a place in other nodelets, and one that contains offsite links. As a workaround, my user account is currently hiding all off-site links from the Leftovers nodelet with CSS rules. While the nodelet is in this state, I will not edit it, not even if I knew more about those sites you're mentioning.
Update: also, if you volunteer to maintain our list of links, whether in the nodelet or in the FAQ, you can apply to join SiteDocClan.
You also have the Free and Personal Nodelets at your disposal. I'm sure you can tweak one (or both) to hold whatever links you like. I've not played with either of them for quite some time, so I don't remember which one is better for your purpose, but when I *did* play with them, they let me do what needed to be done.