I pulled the trigger and went with the BCM94360CS2 and no heatsink. So far, no issues. I have not installed any replacement heatsinks to date and have noticed no issues, which does support the theory that the heatsink is mostly for gaming aesthetics.
The BCM94360CS2 runs circles around the DW1560 in terms of overall support and performance. Auto Unlock now works flawlessly, AirDrop runs much faster with larger files, and Continuity is much snappier and more accurate than before.
If I notice heat issues with the VRMs, I'll definitely just install smaller individual heatsinks on them just for peace of mind. Until then, I can't really complain about performance under load.