I hope that somebody makes one with ample enough spacing to run a full 6-8 higher wattage GPUs, such as GTX 1080 Ti, Rx Vega etc.
Looks like your prayers were answered :
Colorful recently launched a 8 GPU motherboard, similar to the boards in the Pandaminer and clones.
And it's "standard" 2 card spacing, NOT wider for good cooling.
Note that the Pandaminer was designed around PASSIVE COOLED mobile-type GPU cards - one of the reasons it has so many case fans - and thus it can get away with closer spacing while still having good cooling.