Nullama, your guide worked great (besides the few points I raised)! Amazing; I knew about the 20-minute-diff-of-1 feature on Testnet, but hadn't expected to mine
multiple blocks per day.
In fact, I managed to grab almost
30 blocks in 24h.

Sitting at roughly 0.9tBTC right now.
Even consecutive blocks a few times... I must have very good network latency or something.

Only a single Compac F hashing at just under 300GH/s.
It was an awesome experience to solo-mine again (and hit blocks!) and I'll definitely do it again if I need testnet coins and / or for validating a miner / miner driver software.