I find it hard to believe that Beavan wasn't around for HS and Absurd, he probably just doesn't remember them. The track labeled "Old Beavan Mix" on the TWAT New Brain Drums disc is identical to the one on RM1 dated 10/12/00. Silkworms on RM1 is dated only one month later on 11/07/00, while HS on RM3 is dated 11/08/00. Even if Beavan left between the mixing date of RM1 TWAT and RM1 Silkworms, one month is hardly enough time for both Silkworms and HS to be written and have rough mixes prepared.

Adding to that, Beavan says he was still working with the band when Brain joined on. While nothing is confirmed, the drums on the locker versions of both tracks sound very much like Josh, which would mean the songs pre-date Beavan leaving. We can't forget that Josh has a writing credit on Hard Skool too.

Madagascar Old Josh Drums from the New Brain Drums disc is also identical to the version on RM1, dated 11/05/00. This makes it even more plausible for Josh to be the drummer on Silkworms and HS, dated only a few days later.

In my opinion, every song from RM1-4 was mixed by Beavan with Josh on drums, but we don't have enough info to confirm or deny that...

From NJ, skip to 0:45.

It looks like your friend is correct, I see "thinking", "trade-off", "liars", and "veins". I wonder what this means?

Edit: The graphic was there for the two 2020 shows as well.