Floating Selections are only imported as normal layers in GIMP 1.0 releases.
The plugin does not clean up on failure correctly with current gimp 1.1 versions, this means that an image is selectable in the layer dialog which goes away when the list is refreshed. The bad thing is that GIMP crashes if this is selected. Is this a bug in the GIMP code? Is this true anymore?
Linking layers can not be supported 100 percent with current GIMP versions. Furthermore, this only works in GIMP versions 1.1 and later.
Systems other than x86/Linux are not well tested and endian-related problems are to be expected.
Dodge mode layers don't show up in GIMP 1.1 versions prior to March 8, 1999 because the PDB interface has not been updated before - this is in fact a limitation of some of the GIMP versions.
The layer user mask positioning code might need more changes to set correct offsets in all theoretically possible cases.