TL;DR
1. There are no prestige tiers in Adaptive EQ rewards.
2. Bonus milestone rewards are not included in the EQ rewards summary screen
This is an addendum to my previous post:
How Adaptive EQ rewards work that I posted a couple weeks ago. In that post I described the basics of how the new Adaptive EQ reward system works. One thing that came in in that thread, and in several other discussions I've had about the rewards on the Discord and elsewhere involves prestige tiers. There are still people who believe there are prestige tiers. in other words, the rewards are divided into specific prestige "thresholds" and to get higher rewards you need to reach the next prestige threshold.
Some of this belief comes from the fact that the rewards preview screen has actual prestige preview data points. The preview buttons let you preview the rewards for a specific set of prestige points. However, that's just how the interface works. Those are not the only places that rewards change. In fact, this should be apparent from the fact that one of the preview points is always the player's prestige itself. You always see what your own prestige would generate in rewards, even if you are "in between" the normal preview points. Those rewards tend to be slightly different for at least certain rewards.
However, there's another belief out there, that while the 15 or 10 or whatever prestige points in the preview screen are not the *only* prestige brackets, there are still actual prestige brackets, we just can't see them all. Changing your prestige by some small amount will not help you at all unless you cross into the next prestige bracket, where ever that might be.
That's not true. Every single reward awards based on a continuous curve. Given a prestige value, each reward curve spits out a reward as a function of prestige. For each reward, there is both a minimum and maximum prestige to get the reward at all (if you are too low or too high you won't get it), and the reward itself has a minimum and maximum amount it will award. Each reward also has a certain "round off" it obeys, so for example 7* shards will only award in bunches of 100. Whatever the reward system is programmed to give out, it rounds off to 100s. So if the reward system calculates you're supposed to get 33821 shards, it rounds off and gives you 33800.
This round off feature confuses many players into thinking that there are actual prestige brackets, because if you look at just one reward, it doesn't change except in specific jumps. But those jumps don't correspond to anything in particular, just where the round off happens to jump from rounding down to rounding up. And each reward jumps separately, at completely different oddball prestige values. Take T7B fragments. At 26752 prestige Valiants get 41300. At 26753 prestige it jumps to 41400. but there's nothing special about 26753. Tier 3 Class Alloy shards are 2700 at 26752 and also 2700 at 26753. Instead, T3C Alloy shards change from 2700 to 2800 at 26799 prestige.
But the real illustrator of what's going on is gold. Gold rounds off to the nearest 500 gold, but the gold rewards are so high numerically that they actually increase by almost 500 every two prestige. Almost every other point of increase increases you gold rewards:

The gold reward curve is about 225 gold per prestige point (at least at that part of the curve in the Valiant rewards). That means about 450 gold every two points of prestige increase, which means almost every two points of prestige will at least increase gold rewards (it sometimes requires three points because its slightly less than 500 gold per two points of prestige).
Every point of prestige increases your rewards. Round off can make that increase invisible, but each and every reward will round up at completely different prestige points, so there's no actual prestige brackets where rewards increase consistently.
A completely separate factoid I discovered while researching and analyzing EQ rewards: bonus rewards are not shown in the preview screen. If you look in the actual milestones for EQ rewards, you will see milestone rewards, and so-called bonus rewards:

At my prestige, the Elder reward screen shows I should get 13,500 Titan shards. Here are the Titan shards in the Valiant milestones for my prestige:
Milestone 6: 900
Milestone 7: 1600
Milestone 8: 1700
Milestone 9: 2000
Milestone 10: 2200
Milestone 11: 800
Milestone 12: 800
Milestone 13: 800
Milestone 14: 900
Milestone 15: 900
Milestone 16: 900
900+1600+1700+2000+2200+800+800+800+900+900+900 = 13500. So what's the problem? Well, the issue is up there in milestone 16:

Those 4000 Titan shards are not actually shown in the reward preview. Nothing in there is. Now, most of those rewards are of different stuff than we get in the normal milestone rewards: units, mysterium, the give away champion of the month. So while they aren't in there, they don't affect the displayed totals for the stuff that is actually in that display screen. But there are a few cases where that's not the case, and the bonus Titan shards in the Valiant rewards are one such reward.
So when you're looking at the reward screen, keep in mind three things:
1. Make sure you know if you are looking at Classic rewards or Elder rewards, especially now that the top four progression tiers now have an Elder option.
2. Whether you are looking at Classic or Elder, the rewards summarize all of the milestones possible if you fully complete that mode, either full Classic exploration or full Elder completion. Full Classic exploration gets you to milestone 10 while full Elder completion gets you to milestone 16. You do not get all the Classic rewards plus all the Elder rewards; that's not how the system works. For more details, see my previous post linked at the top.
3. The reward screens do not show bonus rewards. Units, Mysterium, and any other bonus rewards will be awarded above and beyond what's shown in the reward summary screen. This can matter for certain rewards, like Titan shards for Valiant players who fully complete Elder.