Prevention of more than four digits in a row collapsing into one Cistercian number

[bartelmarkus]

Hi,
While the font is very fascinating and amazing at showing what OpenType lets you do, I couldn't help but wonder if the "cramming" of an arbitrary amount of decimal digits in a row into one resulting cistercian symbol can be prevented, the way it happens currently if more than four digits are in a row.
For example, the sequence "12222" generates a cistercian number with a bottom-left quadrant that makes no sense.
Would it be possible to only "ligaturize" the digits in blocks of four at a time? Similarly to how Arab or Hebrew is interpreted from right to left, would it even be possible to allow the subdivision of 4-blocks to start at the right of the sequence of digits, effectively converting the number into a "base 10000" number of Cistercian digits?
I know that 13th century monks didn't think of them that way. Though it would frankly make more sense than how longer sequences are compiled right now.
Please apologize if my questions are too out there, since I don't have any background knowledge of typesetting with OpenType.

[tiroj]

I’ll give this some thought. There are no ligatures per se in the way the numbers are built: they’re composed on-the-fly using dynamic positioning. I suspect limiting the number length to four digits at the glyph level will require adding some kind of contextual insertion in the glyph string.