Username Changing needs more QOL

Recently I needed to change my username of 4/5 years. Unfortunately, when I went to change it back a few hours later, I was told that there were too many of my specific username. Ultimately, in hopes of getting it back, I started normally with trying my luck at all hours of the day, and then tried Nitro to force the hand easier, but there's no way to know if a username and discriminator is available. However, choosing Nitro made it significantly harder to get my username, as I then needed to provide an "empty" number, of which I would never have a chance to know without trying all 10,000 combinations as often as possible (due to people changing their usernames and new spots becoming available). This experience was terrible, and these are some suggestions I have on how to fix it.

For example:

Username: [ABC]

Non Nitro User would be given ABC#XXXX if ABC is commonly available, but if it isn't, they could be told that there's still too many. It's annoying still if there *are* numbers still available for ABC, but an idea could be that a non-nitro user could queue up a username change that once a certain percentage of ABC weren't taken (such as 5% of available numbers or more), they would be either automatically changed, or would get some message saying they could change the username. Likewise, if a certain amount of time passes from the initial request and people aren't taking the username, maybe a week, and the number is still within a certain margin (such as above 1%, below 5%) then they could opt to change the username.

For example:
Username: [ABC]

Nitro User wants to change their username to ABC. However, as a Nitro User, they're given the gift of choosing their own number. For the most part, this isn't an issue. As long as they get their username, the number doesn't really matter. However, if ABC isn't commonly available... then they can't change their username without specifying a number. If they keep picking numbers that are taken, they could be there for quite a while. This is an awful experience for the user who just wants their username to be ABC without caring over the numbers.

A suggestion would be that the Nitro User would be told what numbers are available. This wouldn't bring privacy into question, as we're not being given information other than what's available. The information on what isn't available will very rarely be useful as it can't be used to narrow down anyone in particular. For example, for our Nitro User, they could be told

"ABC has 125 discriminators available. Would you like to view them?" 

With this, they're given information that will help them find a number if they're having trouble changing their username, and in the case that all 10,000 numbers are already taken, they don't need to waste their time guessing. Furthermore, in the case where the numbers are much more readily available, it would be made apparent simply by the user seeing that more than 2000 numbers are available, and they would know that they don't really need to look through the list to get that username, or likewise that they are free to be picky since there's plenty of selection.