I contacted f2pool and this is what they told me:
Dear Mr
For the empty blocks, as we confirmed with the ETN develop team, there’s some issues in ETN’s system and they are dealing with it. Anyway, it will not influence your normal mining so much. Cuz the mining mode of F2Pool is PPS.
For the rate of network hashrate, what we wanna say is , the fluctuation of hashrate rating is considered by numbers of miners , not us.
Besides, F2Pool still and will follow the principle of DECENTRALIZATION, and take measures to reduce our ETN hashrate by raising the mining fees or some other methods if it is necessary, just as we announced what we do when our DCR hashrate goes 60% on several months ago. ( For now, our DCR pool hashrate ranges about 20% of the network hashrate), to prevent the possibility of 51% attack.
