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.
The result is much better compared with when i mined with GPU. It looks like getting tBTC isn't that hard for those who already own ASIC.
PS: Check last 24h of blocks for hidden message!

Using blockchair help[1], did you send message "cgminer42 solo on Compac F"?
What needs to be changed for this to work on main net? Remove testnet=1 ?
That's correct. But don't expect to mine any block unless you're lucky.
[1]
https://blockchair.com/bitcoin/testnet/blocks#f=id,time,fee,fee_usd,coinbase_data_bin