after small digging they have Full VSCode debugging [0] which is nice. RN have Radon IDE but it's a paid sub. What's interesting Valdi using Hermes (the one from RN) so maybe there is a way to retrofit this to work for RN. Wondering if they did AOT and JIT by themselve or they using static hermes branch or using only hermes in dev mode.

[0] https://github.com/Snapchat/Valdi/blob/main/docs/docs/workfl...