Between keep all BP or wipe all, I'd choose wipe it all.
The only thing I would really really really want to save over are basic building stuff: floor grill, cell wall, ladders hatches, dropbox, and chainlink fence blueprints. Those don't really do anything in PvE except offer players more taste and preference in what they want to build for their base/homes, and to hide them behind RNG crate-searching and scrap-grinding really melts the spirit. Everything else can go, though.