you already mentioned that you are a small team with limited resources which can cause a long approval time for Build Service Requests.
There I have a suggestion you maybe can add to your services: Something like a premium request service. Therefor you charge a special amount per whitelist request but then it's definitely done in X days. I think a good number would be around 5 days.
I suggest this since if you have a big live game and need fast / important updates to a huge community, you also have enough money to pay for a "premium request service". I don't really know how much time (work hours) it needs to whitelist a single addon, but maybe 100 USD per request would be a fair amount. Even if it would be more I would have used this service several times in the past, but also interested for feature requests.
For example I saw a Build Service Request opened 21 days ago. For "real" publishers this could be very huge problem if you need to react fast (maybe important update or whatever).
I don't know if something like this is even possible, but if yes, it would be a very great improvement!
Thanks for your time!