None of those look large.
savehist doesn't truncate anything AFAICS.
It just assumes variables are trimmed by add-to-history etc in the
course of normal operation. So if you add a non-history variable to
savehist (or set history-length to t), it will eventually blow up.
Hmm, ok. I may have misunderstood savehist's role then, I thought that savehist managed history size. Eli, apparently the savehist-trim-history function is only used on XEmacs--it's a noop on Emacs.
Sorry for the confusion then. First bug report :D ... failed bug report :( . I'll talk to Spacemacs folks about fixing their configuration to guard these variables accordingly. Thanks for your time!