Thanks, everyone, for advice and encouragement. Eh-m, back to ground zero (been asked to drop the acronym), is PDF::Manipulate (rather, PDF::Manipulate::X) an OK name? (Contra: Verb as 2nd term? Too long? Negative connotations?) I considered "Parser", or "Wielder", or "ReadWrite", but like them even less. "Manipulate" is in the very 1st sentence on CAM::PDF pod page. In essence, I consider (and use) CAM::PDF as low level parser and manipulator with few high level methods, a tool for other developers to make (high level) tools.
Why "X"? PDF::CAMPDF::X would have eXtended CAM::PDF to serve as drop-in replacement in any existing code. PDF::CAMPDF::X2 would, in turn, subclass it but get rid of CAM::PDF::Node (blessed-for-no-reason constant-keys-set hashrefs) and use arrayrefs for "nodes". An exploration at first, how much of a performance boost that would add. Would be advised for new code, can't serve as drop-in CAM::PDF replacement. Because see e.g. line#82, and many more, in CAM::PDF::Annot accessing "{value}"; poking inside "nodes" is all over any code using CAM:PDF.
So then the idea now is to have PDF::Manipulate::X and PDF::Manipulate::X2 in the same distribution and kind of on "same depth level". Unless, that is, strongly advised not to. I'll think about how to properly and carefully document everything.