What's cons?
Everything in that paper by dga is addressed in more recent versions of the Cuckoo Cycle whitepaper (e.g. the version published in BITCOIN'2015 from Jan 2015).
Good, you should send it to the next tradeoff-resistant algorithm competition.
There are no PoW competitions. But I will be happy to submit once there are.
The only thing left is to note that your statement
"PoW blockchains are inherently vulnerable to QCs"
only applies to PoWs where a huge range (at least billions) of nonces is searched
(by one miner in one block interval).