just be aware that if you have multiple palettes you can't use the indexed screens, you have to use the rgb32 ones instead of ind16
it can get a bit messy.
also there's the core problem with multiple screens you might run into with complex setups, whereby if you have 2 screens running at different refresh rates one of them won't update properly (the partial update system gets very confused because it expects both the screens to end at the same time and if that isn't the case large parts of one screen end up not updating at all)