Do you have any experience with the XT-705A you can share? I would be very interested in hearing about the heat generated by the media converter, and if there is a way to disable flow control.
Heat wise the unit is warm to the touch, a few degrees above body temperature, just now. As this is used in a residential setting I guess you can hardly claim I'm pushing the capabilities of the device at the moment, especially as it's just running the NBASE-T port at 1gbit/s to my Edgerouter Lite.
I did some tests yesterday with a second NBASE-T card connected directly to it, where I saw throughput numbers of 2.5-4Gbps, but could not notice any difference in temperature.
It's also a fairly low energy consumption, rated at 3.75W maximum (which must include the SFP+ module at that), and the specs mention 12.8 BTU per hour.
There is no configurable options exposed on my end of things, so I think the flow control is locked in place. I do not believe this converter has any options exposed at all, while the 1gbit/s converter (GT-805A) used before has a management interface exposed on the SFP+ port.
Not impossible that there is some type of way to have it disabled, but I'd guess you better shoot a mail to the support over at Planet to verify that.