My suggestion is fairly simple, but one that I think will have a wide-reaching and positive influence on the Arelith world, and especially the new player experience.
Rather than limit races to "you need to have an X reward", limit them to "You must not have negative rewards"
This system would work better if/when the epic sacrifice system was switched to a point based system, but it could work, though a bit awkwardly, in the current system (Must not have less than 0 of ["any award" OR "Specified award"])
There would still be the current limitations of RPR requirements and applications, and a new requirement to use a reward race: Must not have the new player flag (assuming that's not already a thing)
Why? Three reasons
First: One of my personally most frustrating moments during concept creation is the realization that my awesome character I'm getting excited for isn't possible because it requires a greater or something. As I've played on this server for a longer and longer period of time, I've come to memorize which races require it, and so I don't run into it as often, but it was FREQUENT as a new player. This change would allow a newer player to utilize the more exotic races they've gotten excited, while still achieving the desired server goal of keeping them rare. It is important for the new player experience to put the fewest barriers in front of them as possible, while still meeting other game requirements.
Second: The newer players this would mostly impact are more likely to make weird RP builds, both because they're still exploring what's available on the server, and they simply don't know the meta. This means this change would introduce a lot more wacky and interesting character builds, like derro fighters, Ghostwise halfling shadow sorcerers, and pixie paladins.
And third, newer players are more likely to simply abandon their characters, or perhaps the server overall, which means this change likely, in the long term, won't even have that big of an impact besides the above.
The biggest hazard: Applying this change to the currently active player base will result in an obscene surge in all the rarer races, as every experienced player gains the ability to make one at once. To mitigate this, I would recommend rollout be done in fairly lengthy stages. First: 40+ RPR players get it. Being experienced players, they should be responsible enough to use the change responsibly, and this'll give the team an opportunity to discover and address any additional pain points.
Then, around 1 month or two later, or when the racial spread returns mostly to mean, we can roll them out to the 30 and 20 RPR players. We could potentially stop here, if there's significant concern about the RP quality of these races, but, since the poor RP would still exist, just on more boring races, I don't think it's worth stopping here.
Finally, perhaps as much as 4 months later, depending on how fast the return to mean is, it's rolled out to the 10 RPR players, so long as they do not have the new player flag. Chaos commences, but it should settle down pretty rapidly, as players experiment with the various newly available options before settling on one or none.
Note: I am unsure on the spread. If 20 RPR players are a significant bulk of players (30%+), they should probably be their own stage.
I also am of the opinion this mechanic should not be applied to people that have 0 RPR. If you've proven to be a little turd, you lose your fun races privileges. This could also potentially give DMs another mallet to utilize, perhaps independent of RPR. Not sure why that'd be useful, aside from some edge case where people fail to roleplay their races like, at all, but hey, more tools in the toolbox. Perhaps if you've been smacked by a DM at all, you lose it for a month? Options!