For what it's worth, I think that Judge Bea not only gets this one right, but also writes a moderate and reasonable -- and persuasive -- opinion.
Yes, when defendants invoke the right to counsel, we can't use that against them at trial or to defeat their insanity defense. But, Judge Bea (rightly, in my view) holds, at least under California's bifurcated procedure, we can use the fact that they invoked as evidence that they may not be incompetent to stand trial; e.g., that they're capable of helping in their defense.
I think that the two stages are sufficiently different to justify the differential treatment. So I'm on board for this one.