[NTG-context] [***SPAM***] Eliminating orpans in the Index

Hello Everyone, in my two-column index there are several cases when the last entry in the given letter group overflows to the next column/page. In the extreme case it is just the last page reference. Can I somehow prevent this? E.g. keep at least two/three index entries together when the overflowing is triggered? And always keep all the page references together? Additionaly, columns are not balanced properly in all cases. When the first is longer, it is not a big problem. But the opposite case looks weird. Can I influence this behaviour? Thanks, Jan PS: Grid is not activated.