One Google account gives you one allowance. Several give you several, and a server that switches between them when one runs out keeps a long run moving.
That is the whole idea, and it works. What is worth saying plainly is what it does not do, and what it asks you to hold on disk.
If your script waits until midnight for the quota to reset, it is waiting for something that no longer happens. On 2 September 2026 Google replaced NotebookLM's fixed daily chat caps with a compute-based allowance that refreshes every five hours, up to a weekly ceiling.
Our own documentation said "50 queries per day, resets at midnight UTC" until this week. It was wrong, and we had been repeating it for months.