Evening feed are often clustered. It doesn't have to be a cluster exactly as the book says, you can feed at 5pm (so it is a bit early, 2.5hr instead of 3) and again at 6pm ready for him to go to sleep if you think it will help. It does of course depend how long he takes to eat, if it's taking a long time then one appears to almost run into the other. Once he's asleep I'd let him wake for a feed if that is 8pm or 8.30 that's fine. I'd probably treat it as a night feed so straight back to bed and to sleep after eating (change of nappy if needed). DF or NF at around 10 or 10.30pm and night feeds thereafter every 3 or more hours.
Mine was still feeding every 2.5hrs at 4wks. I remember it because it was during that week I was given a BW book and read about the 3hrly E. I started to stretch him just a few mins at a time aiming to get closer to 3hrs from that point. The 2.5hr feeds were frequent, by the time one was finished, the nappy changed and a nap had the next feed came back around before the blink of an eye.
Even when his feeds were 3hrly and he was bigger we often had a very short gap between the last day feed and the BT feed. I just always gave him the pre-BT feed no matter how recently he had eaten, then the NF/DF around 10pm.