Yes it is an interesting model.
However for it to work we would have to have something in the neighbourhood of about 100BTC held in the PoS pool staking to make any kind of dent in it.
Maybe they got some kind of crypto magic.
We do plan to build a 'remining' feature into the pool in the future where people can take their earnings and turn them into more hash power to redouble their earnings until they withdraw. That's in the future though.
We likely do have to look at something with PoS somehow working with the pool in the future. Many alts are using PoS now and it is making it more difficult to find good coins to mine. Often there is conflicting information about a coin and we only find out the hard way later about it.