Indeed actual SMIRF could import a whole list of proposed FEN extensions concerning Chess960, and of course the PGNs, which are using them, too.
The problematic FEN extension used by the new Shredder (incompatible to X-FEN) is also part of that list.
Nevertheless SMIRF always will save and export FENs and PGNs only compatibly to X-FEN.
And in all cases that would not be a solution for the related compatibility problems e.g. with other GUIs, game databases, online chess servers and PGN viewers.
Reinhard.
http://de.geocities.com/rsmuenchen/ (SMIRF)