I’m not sure whether you’re trying to make another real-time upload happy or just avoid hogging. Hogging can probably be avoided by throttling down, but the minimum burstiness probably comes from Microsoft:
Upload bytes to the upload session
the size of each byte range MUST be a multiple of 320 KiB (327,680 bytes).
Do you think that’s relevant? Issues exist (as you can see from GitHub). Volunteers are much needed.