I'm definitely supportive of the original "Symbols for Legacy Computers" effort. We've been able to make great use of it in the llvm-mos toolchain for legacy systems; we can directly encode special characters for these computers directly in the UTF-8 source text of modern C++, then use C++ user-defined string literals to convert them to their original byte codes. It's an aid to hobbyist use and preservation of these systems, and thankfully, there's a relatively small fixed number of them to support, especially relative to the space available in Unicode. It should unlock quite a few of these kinds of projects for exploring and experiencing the history of computing.
https://llvm-mos.org/wiki/Character_set