The following project has a more advanced decompiler as far as I know: https://github.com/lucasbaizer2/hasmer/tree/master/hasmer/libhasmer/Decompiler
Unfortunately the disassembler of this project it's not quite up to date with the latest HBC bytecode versions. Any chance hermes-dec could use its own disassembler and https://github.com/lucasbaizer2/hasmer as a backend for decompilation?