Default FILEPOSITION(FALSE) on indexes

Is there any disadvantage in defaulting this on?  Potentially wasted space (especially in memory) for the current index formats (although 0's will compress very well on disk).

If we have an index format that either doesn't store it if not required, or compresses all zeros into a single bit then it would potentially avoid the need to copy the data in strange ways, and avoid the need to promote the type of the last field.