Sounds interesting. Just be aware that the chips are 0.4mm pitch MLFs with glued on heatsinks and no well done self-centering pads.
Most hashing MLF/QFN type chips have a pretty big center pad to wick heat and/or 2 pads in the center to provide +12 and ground. Soldering around the edges is difficult, but not too too bad. The key is a very good flux and proper board pre-heating.
I'll have to take a look at the S9's. The real nightmares are sub .4mm BGAs.....