Have you guys looked at Cuckoo cycle?
FWIW we evaluated Cuckoo as well for Zcash, and it was a strong second-place contender. There wasn't really anything wrong with it it just didn't seem to have quite as much of a rigorous scientific analysis as Equihash. However, that is a very subjective thing for me to say. You could argue (and Cuckoo's author, John Tromp, does argue persuasively) that Cuckoo's history of analysis and refinement is better than Equihash's.
What about cycling through 10 unique PoWs every 10 blocks?
I'm not the best at discrete analysis and understand this multiplies attack surface 10-fold, but could we splinter miners into small, specialized, and de-fanged factions using 10 different well-chosen hash algorithms, then scatter them among CPUs/GPUs/FPGAs/ASICs?
Block 1 JH
Block 2 Skein
Block 3 Groestl
Block 4 Cuckoo
Block 5 Keccak
Block 6 Equihash
Block 7 BLAKE2
Block 8 SCrypt
Block 9 CryptoNight
Block 10 Ethash
Wont this make difficulty rise and fall like a wave? If the answer is yes, then wont this open the network to attacks if there is a fall in difficulty. Maybe it wont be the case after a year but in the beginning it could be.
If youre going that road, why not have 2 POW algorithm at first with the option of expanding it instead of starting with 10 outright.