Not really - most users seem to either want their backups to run as fast as possible using all available resources OR run as slow as necessary so as NOT to use all available resources.
Personally, I don’t care how long the backups take so I use --use-background-io-priority=true and --thread-priority=idle.
You may find that adjusting --throttle-upload and some of the concurrency settings (such as --concurrency-max-threads) might give you the speed / performance balance you seem to be looking for.