The "Higher tiers no longer less efficient" thing, is only for the Massfabricator?
Other machines will continue being less efficient?
Yes, that's likely it, according it's writter in Mass Fabricator tab.
I also suggested next idea for generators - make possible to low output of generators to acquire power efficiency. For that I came up with three possibilities.
First way: MV steam turbine with basic efficiency of 75% is able to output 32 eu/t with the same efficiency as LV one, but with 4 Amps (so in fact it's 4 LV steam turbines, just more compact and requires different material to craft - cheaper in some sense). This is sort of how Greg would've done it. A "fair" way.
Second way: MV steam turbine with basic efficiency of 75% will go up 95% if it's output mode is set to LV.
Third way (almost simmilar to second one): All steam turbines have by default the same efficiency of let's say 85%, but
for example, if you set MV steam turbine to output LV voltage, it's efficiency will growo up to 95%.
Numbers are obviously not precise there. I should mention, that 1-block turbines should never be more efficient than large ones.