Indeed I did some tests too (only on type VIIa for the moment).
With stock value, I traveled 18h at 4 knots, run a distance of 120km, battery left 4%, CO2 35%.
With corrected value, I traveled 26h at 4 knots, run a distance of 180km, battery left 3%, CO2 54%

.
The technical spec for a VIIa is 94miles@4 knots, that being so 174km@4 knots.
So I think the bug is still there, and the solution too.
About the CO2 level, we had exactly the same problem with SHIII, general thinking was that a 10 factor was faulthy harcoded. We twicked the display by the same factor. OSHA's maximum safe level is 3%; lethal concentration (death in 30 minutes) is 10%.