Efficient API to stream from a MetadataReader to a MetadataBuilder with modifications

Rewriting IL using System.Reflection.Metadata seems to bit a bit of a mind-melting endeavor. Due to the order-dependent relations between the tables, and most binary blobs needing row references to be patched, I haven't been able to find a scalable pattern for a single-pass read and write. It feels like something like this should be in theory possible. Maybe with something like a visitor pattern?

I'd like to do some things that are purely additive, such as inserting a module initializer, and others that subtract or modify rows, like generating ref assemblies from third party framework implementation assemblies. Some of these things will slow down every build because I want to put them in post-processing NuGet packages, so one goal is absolutely minimal overhead.

Does this sound like something that can be made generally useful and that you'd be willing to accept in SR.Metadata and keep up to date?