Both splits are valid and I have seen both used successfully. Boris programs enough work to be successful even under less than ideal circumstances.
Maybe there can be made some points about hypertrophy stimulus being greater when you do the secondwave with more fatigue, so both being in one workout. However, for lifting as a skill, having an exposure to the lift in both sessions, so noon bench, evening bench, is definitely resulting in greater technical learning.
So while tending to the latter option, if you feel like one of the two options is better for yourself or you just like it more, I would go with your personal preference.