That's already taken care of; if it's luckier to discover a luckier luck potion than the Philosopher's Stone, then that's what I would discover. And of course, by induction, then subsequent consumption will result in even luckier potions (since luck presumably compounds so any subsequent improvements will still be luckier than a PS's discovery).

If there is no luckier potion or the Luckularity would hit a plateau, then I would be better off with the PS and hence the luck and preference would line up. So seeking the PS is the dominant strategy.