The only advantage of taking the entire dose in the morning is supposedly the risk of developing adrenal insufficiency is less. Cortisol release from the adrenal glands follows a circadian rhythm with cortisol levels starting to decrease when we are getting ready for bed and increasing prior to waking up. Prednisone taken in the evening interferes with this sleep/wake cycle so it makes it hard for some people to fall asleep.

The artificial cortisol from Prednisone replaces the cortisol from the adrenal glands. Taking Prednisone in the early morning mimics the circadian rhythm of cortisol release more closely. I woke up in pain at 3 a.m. so that was when I took Prednisone. Prednisone doesn't stay in the system for a full 24 hours so the inflammation reducing effects were wearing off at about 3 a.m.

When I took my entire dose in the morning at 8 a. m. the early morning pain also disrupted my sleep/wake cycle. With a split dose, most of my Prednisone dose was at 8 a.m. while the rest in the evening allowed me to sleep the entire night without pain. I took 2/3 of the dose in the morning and 1/3 of the dose in the evening.

This link explains the sleep/wake cycle of cortisol release and how cortisol levels affect sleep.
https://sleepdoctor.com/how-sleep-works/cortisol/
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When I wasn't having pain in the middle of the night, I switched to taking my entire dose at 8 a.m. in the morning:

See the link below.
#6. Morning dosages are usually best for prednisone
If you take prednisone daily, for a long period, it can cause adrenal gland suppression. This is when your body stops producing cortisol by itself.

If you are on daily prednisone, experts recommend taking the dose in the morning, to reduce this risk. Taking prednisone too late in the evening can cause sleeplessness and insomnia, too. Make sure you also take your dose of prednisone with food, and just FYI, grapefruit juice has no effect on prednisone.

Prednisone has long-lasting effects and is usually prescribed once daily. Occasionally, people on higher dosages are instructed to take it twice a day for short periods before dropping it down to just a single dose.
https://www.drugs.com/medical-answers/prednisone-12-things-you-3573757/b
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By the way ... I don't think the early more pain had anything to do with a "new batch of inflammatory substances being released and they needed to be mopped up with Prednisone."

The inflammation is chronic so it is there all the time. Either cortisol or Prednisone is needed to regulate inflammation levels. If we decide to take Prednisone then the body turns off the production of cortisol. The cortisol suppressing effects caused by Prednisone makes it difficult to taper off Prednisone.