[***Heads up, this is a 2 1/2 year old thread***]
 
That particular driver has gotten attention because there are a lot of comments about it not being backwards compatible. For the VIA chipset specifically, that also worked well in Win7, but in newer OSs support only references TI chipset cards. For me, Win10 (1803) also triggered an issue in MixControl 3.6 (even on a TI chipset card) that was observed in the Macs, specifically that audio output was disabled unless the FW latency was changed in MixControl (and not possible if used as the default Win10 device).
 
Both the legacy driver and MixControl 3.4 are pre-Win10, and that combination seems to function wthout issues in Win10 for most folks using Saffires. Just of note, that second article is from 2016, and since then ALL FW (Saffires) are legacy... Focusrite doesn't sell them anymore... there are no "modern Saffire interfaces" now.