I've never had the impression that the VMS has spelling variations. The text is so remarkably consistent from beginning to end (even taking into consideration the Currier "dialects"). It is almost too consistent. If there are spelling variations, I suspect they are rare.
There might be abbreviations (the 9 abbreviation for endings and sometimes beginnings is one of the most common abbreviations in medieval texts, everyone knew it and most of them used it, so if there are abbreviations in the VMS, perhaps this is one of them).
But if there are abbreviations, they would have to be applied fairly consistently, rather than being written in different ways, or the VMS text would be more varied in terms of glyph position, and the overall makeup of the tokens.
There might be abbreviations (the 9 abbreviation for endings and sometimes beginnings is one of the most common abbreviations in medieval texts, everyone knew it and most of them used it, so if there are abbreviations in the VMS, perhaps this is one of them).
But if there are abbreviations, they would have to be applied fairly consistently, rather than being written in different ways, or the VMS text would be more varied in terms of glyph position, and the overall makeup of the tokens.