This project only works with IEnumerable, not IQueryable, see https://github.com/antiufo/roslyn-linq-rewrite/blob/09216a3b2ab53474a93db861435c056523f194d0/Rosly

This project only works with IEnumerable, not IQueryable, see https://github.com/antiufo/roslyn-linq-rewrite/blob/09216a3b2ab53474a93db861435c056523f194d0/RoslynLinqRewrite/RoslynLinqRewrite/LinqRewriter.Rules.cs#L167-L181 https://github.com/antiufo/roslyn-linq-rewrite/blob/09216a3b... for instance. I guess this is for exactly the reasons you talk about, i.e. once it's working with Expression tress too much is unknown and any optimisations would be v. risky.