On T8 delves, the tooltip for the Zekvir’s Influence affix says that defeating empowered mobs grants extra Delver’s Journey XP, but I always get 150 XP for completing a bountiful delve and another 200 from the bountiful chest regardless of whether or not I cleared the empowered mobs.
Since lower tiers reward less Delver’s Journey XP, my guess is that Zekvir’s Influence just bumps the rewards for that tier regardless of whether you actually clear the Zekvir-empowered groups, and the tooltip is just poorly worded.
Not really anything important; just something I noticed that made me curious.