I can't say I've analysed everything he claimed. However, it's interesting that much of what he's claimed (from what I can see) is about actions/issues/decisions (etc) which were reported at the time and quickly brushed under the carpet and forgotten about. I think he's telling the truth about them.
If people are saying that we should wait and see if what he's saying is true then they haven't been following developments over the past year or so. I'm not saying all of it is true but much of it has been written about in articles by others, such as investigative reporters. The book, Failures of the State' which was published earlier this year, and which I have read, is by two Sunday Times reporters who have used a number of sources, news items, minutes of meetings and interviews with people from many areas, sets out much of what Cummings has said. There is already plenty of corroboration out there.
Like Pippa I would be interested to see all these threads about Cummings 'running the country'. As far as I recall there was a lot of discussion of his little jaunt to Durham (and, BTW, I think he is still lying about aspects of it, such as the 'mob' at his house. There was no 'mob' until the news broke about his trip, and then it consisted mostly of reporters and photographers. AS GG13 has pointed out. I recall one socially distanced protest, too, but not 'mobs') but not much else.
He didn't say much that was unfamiliar to those who had been keeping their eyes open...
I certainly don't think he's a white knight.