when it is safe to save()?

I tried for the first time to call save() when my code in DS-D6 watch is somewhat usable but after saving, the console and my code stopped working. When connecting via Bluetooth I see ->Bluetooth on serial and I can also see switching back message when disconnecting bluetooth but I cannot enter any commands (both in serial and bluetooth console) and also my code (setWatch - touch button to show time) is not working anymore.

After power cycle it boots into console prompt but after few seconds it freezes.So I guess it is maybe some setWatch which is triggering something not initialized? I managed to type reset() quickly after another powercycle so it is OK now.

The answer in FAQ says that timers, watches, and even pin state is restored however it also says " For certain things (like initialising connected hardware like displays) you'll want to run some code when Espruino starts up".

This feature of restoring "timers, watches, and even pin state" seems a bit dangerous to me because even some pin state may make sense only with some prior hardware initialization.

Would it be useful or even doable for save() to just save code without any other state that runs code (timers,..)?

To me it means that I should be either extra careful in all my watches and timers to check for uninitialized or simply random state (which could be tricky with attached hardware with its own state) or better I should not start anything before running save() - just call reset(), load pure code without starting/initializing anything and then run save(). Also I see command history is saved too probably eating memory (as all my code is pasted there line by line), can this be cleared before running save?

Apart from the faq question there is also https://www.espruino.com/Reference#l__gl­obal_save with no hints or more details. Is there some other turorial or ducumentation related to this?

EDIT: BTW, the saving and loading itself went fine, when saving it compressed fine and did fit into memory so there was no issue with that.

EDIT2: Oh, found also this https://www.espruino.com/Saving with some Gotchas
but still I don't understand why it stopped working imediatelly after calling save()