RE: Shocking
Apache, since Reiko has indicated that optimal performance is not a key requirement, then having some air in the shock body should handle the volume absorbtion issue. Some foaming of the oil will result, but it isn't a big deal. Associated has used this very method in their competition racing shocks for years with NO isolation bladder or closed cell foam. If it's good enough for Associated, who are racing and always looking for handling advantages, then I see no issue on a fancy dancy show truck.
Additionally, with the internal spring setup, there is less room for bladder or foam block.