Let me preface this by saying that civil procedure and criminal procedure are separate bodies of law with their own rules on these issues. I’m not a criminal attorney and thus not comfortable speaking out of field. That said, I know there is an analogous work product doctrine that applies to pro se criminal defendants, but I don’t know the contours of it.

It’s super interesting to think about though! Imagine if your Google Doc said something like “The stolen cash is hidden in these six places, but the prosecutors don’t seem to have anything linking me to some of those areas, so I should point that out at trial.” If the government didn’t already know where the cash was hidden, it seems implausible to me that any judge wouldn’t let them have that information. It likewise seems implausible that the judge would let the prosecutors know what the defendant thinks would be good or bad to emphasize at trial. So I’m guessing it’d be an in-camera review resulting in a redacted document just disclosing the places where the cash was hidden, but not the subsequent mental impressions. But the real question, as you asked, is whether you can actually put that in front of a jury to show guilt. And I’m afraid I’m going to have to plead ignorance here (but hope there are some criminal attorneys lurking on HN that could speak to this).

I don't have an answer to this- but if the above answer was based on the Federal Rules of Civil Procedure it may not apply to criminal cases at all. (And the above was probably a generalization that assumes parties in California or some other state the lawyer was familiar with.)