Glad it worked! Flow control is a strange one as it’s a parameter that’s supposed to be auto-negotiated between the device and the switch. The problem is that with some implementations both sides come to an agreement, but one side doesn’t actually follow it. I had a strange issue with a Mac Mini a few years ago in which it wasn’t getting along with a Cisco switch. Can’t remember the specifics, but the Realtek NIC in the mini wasn’t living up to its end of the bargain and until Cisco implemented a firmware fix I had to manually configure the switch port and NIC.
You’ll likely find that your 10/100 switch works without a hitch.
It already does this (mostly) on the core, hence the large bursts of traffic you were seeing from the NAS. To the endpoint, though it’s still a carefully metered stream into a properly-sized buffer on the remote end. This has a number of benefits in terms of endpoint design and is one of the things that allows RAAT to do multiroom at high resolutions.