Anyone have thoughts on the Spacement white paper? Particularly the part where they mention BURST:

"The most notable security issue with Burstcoin is time-memory tradeoffs: a miner doing just a little extra computation can mine at the same rate as an honest miner, while using just a small fraction (e.g., 10%) of the space."

See the end of page 4 and also end of page 26 thru 28:
https://eprint.iacr.org/2015/528.pdf

There also mention some other problems related to verification and nothing-at-stake or grinding. Seems like these guys are the real deal, half of them from MIT.

Edit: Also, is v1.2.3 still OK to use?