You really should draw a proper network diagram and then we can talk about the individual rules. Also note that it’s not a single rule that in itself does all the things you want, but a set of them that work together.
The whole scenario is discussed btw in quite some detail in the thread that lead to your second reference in your first post here:
http://forum.mikrotik.com/t/1-1-nat-dnat-configuration-help/182840/1
Where is the laptop in the network? I assume that because it has no gateway set on purpose, it’s in the place of the plc/hmi/whatever device. You are testing a connection initiated from this device. Is this the actual use case?
And yes, proper src/dst-nat rules do solve exactly the issues with the gateway, (I think in these situations you would be better off not src/dst-natting individual addresses, but mapping entire /24 subnets, as I described in the previous post. Here netmap will be the appropriate action.)