I fell very far down this rabbit hole trying to figure out the history of library link orders and symbol resolution. One fun outcome of which was finding that the first ever public release of a manpage for ld.so on Linux listed RPATH as deprecated. Finding mailing lists from before the source ware transition is hard, some of it exists if you follow the path back to the Solaris forums, but only some. I’ll look through my archives for the features you listed, but I don’t think I uncovered anything about them specifically. Good luck!