In Germany, those who knew Alois claimed he was never wrong.
Yes, many direct witnesses have been interviewed, since it wasn't ALL that long ago when he was still live, and some of his predicitions have been docuмented as having been made beforehand, since they had been published somewhere and could be dated. There's one controversial docuмent out there that appears to have mentioned something about 9/11, but since it came out after 9/11 (by some years), there's controversy about whether it was genuine, or even if genuine, the part about 9/11 interpolated into it. But despite one or two cases like that, many of them can be verified.
I find this one about the short-notice peace conference in Budapest coming after everyone calling out "Shalom!" (Trump's so-called "Eternal Peace"), since it was obtained by a direct witness to Irlmaier and published many years ago -- very intriguing. There's a discrepancy where one individual who interviewed this same "witness to Irlmaier" said "Bucharest", and the other "Budapest", but that actually speaks to the veracity of this source more than if they had been consistent, since you can't accuse one of just copying from the other.
To me this clearly suggests someone having relied on a hand-written note, a primary source, since all you have to do to transform Budapest into Bucharest is, in cursive script, leave the "d" slightly open (unclosed at the top), and then leave your "p" slightly open without a strong dip beneath the line for the vertical stroke, which I could probably replicate right now ... so that some slightly-sloppy cursive script could easily account for that discrepancy.