Yeah, there should be no space problems when portrait changing. It's totally cut & paste -- as long as the inserted images are the same color depth as the originals, it's a clean replace. Unless Vehek or justin3009 have run into any problems I don't know about.
We can start a polling thread to generate some excitement in the community soon. Where should it go? Kajar Labs or Chrono Casual Discussion? I know where to get Crono, and Vehek's supplied suitable Lucca, Robo, and Magus arts to show off (and I'll supply my copy of the Prophet's Guile portrait for Magus as well). We need Marle, Ayla, and Frog artwork. I'll default to cutouts from CuteLucca's Final Techs Series. Then we can ask the community for input I guess.
I haven't done a thing for Crimson Echoes yet, but I'll start the polling thread tomorrow if you guys will it so.