We are currently in the process of running a 200,000 sol (yes that is not a typo) GPU mining test against the notaries.

This is to verify proper behavior under such extreme conditions. So current ROI will be meaningless as I dont expect anywhere this amount of hashrate to remain active after the test. (Unless KMD price skyrockets)

under normal conditions, the external miners are expected to get 20% of blocks and the amount would depend on the total hashrate as usual.

currently the external mining is getting 40% of blocks and we are investigating the reason why. I think just some transition issues as it is the weekend and I know some people believe in them still