Unless your download runs faster, is weeks (if not months) acceptable for restore in case of disaster?
Also on the speed topic, I think throttling is confused, so if upload throttle doesn’t throttle the uploads, setting the same value for download throttle might solve it. Direction confusion may vary with version.
Third party Windows software can do this, and possibly Linux and similar can do this without add-ons.
6 best bandwidth limiter tools for Windows 10 (just to use a sample article to support above comment)