From the paper, Elevator currently supports only single-threaded binaries, does not support binaries using exception handling, has unsupported x64 extensions, and does not support self-modifying or JIT-compiled code. Slack is Electorn based, so t embeds Chromium and Node and depends on V8.

Maybe try an emulator? There's also this project I found: https://github.com/andirsun/Slacky

Just curious, is there anything the Electron wrapper provides over the web/PWA version, other than the drawing feature?