Is it possible to sort fields or facets using custom Collator ? I found only one solution for fields solr.CollationKeyFilterFactory filter but there are some problems with this solution. First problem is, the solution doesn't work with facet sorting. Second problem is that it is additional field so index size is increased.
My solution for facets is to develop own facet component with Collator parameter. For other non facet fields I need implement my own field type with Collator.
Problem is that solr Facet component isn't easy extensible because it has private embedded classes.