Which pool would be ideally the best for the E3?
I'm willing to bet that basically any Ethash pool should work on the E3, Z9 mini only supposedly had issues because it was submitting shares extremely quickly compared to GPUs and the pool would reject shares from the miner as a result.
I think until you get your $1876+ back, +power costs, pool fees and software fees, this asic will turn into $15 scrap metal, as many other models did. With gpus you will lost much less.
You're forgetting the many people who bought the E3 at $800- even with today's mining environment, the break even time at that price and $0.10/kWh electricity is still well under a year as of now and likely won't explode as much as previous algos without ASICs like X11- the E3 isn't a lot more powerful than a GPU rig and some fine-tuned GPU rigs can outperform the E3 in both power and hashrate performance, though I do agree difficulty will indeed rise and profitability will drop, although I don't think it'll be as much as algos like X11 or Blake2b in the past.