For exploration you don't need the powerplant thermal efficiency to be less that 0.50, you can sit on a star scooping max fuel and under 70% heat. I do not understand reducing it any further for pure exploration ships... unless your ship is multiuse i.e. mining & exploring. But I follow the philosophy of min-maxing ships for specific tasks. For me in exploration, whether its going to beagle pointe or discovering all codex entries in a sector, jump range is king.
Explorer Anaconda Build (
78.24 ly with Full Tank ) -
https://s.orbis.zone/d84p
Explorer Phantom Build, New FSD (
72.91 ly with Full Tank ) -
https://s.orbis.zone/d84o
Explorer DBS Build, New FSD (
74.60 ly with Full Tank ) -
https://s.orbis.zone/d84m