That is due to some sort of upload "master limit" at our end unrelated to per-account storage limits (or lack thereof for Unlimited accounts).
It's taking so long to resolve this because Dev thought they'd already removed anything that would limit uploads for clients on an Unlimited plan, so they're not sure where this restriction is coming from and having to review our uploader code line-by-line (and wherever else that code may point) to figure it out.
We will followup with your email ticket about this issue once the matter is resolved; there is nothing you or we can do about it until Dev identifies the source of the restriction. We do apologize for the inconvenience and thank you for your patience and cooperation.
