> wrangling hand written modules with enormous I/O, stitching IP together

This is something where I'm confident a good type system can help significantly, part of the problem imo is that the module interfaces are often communicated with prefixes on variable names. The Spade type system bundles them together as one interface, and with methods on that interface you can start to transform things in a predictable way

Generating memory maps is also an obvious problem to solve with a language that attaches more semantics to things. I haven't looked into it with Spade, but I believe the Clash people are working on something there