A couple of electrics questions.

[unfazed]

To lower the electrical load I have fitted LED lights - made a massive difference.

Same here and I replaced the White connector with Anderson powerpoles.
Plans are to do something similar with one of the connectors under the infill panel.
The original wring and connectors are fine, but when water especially salt water gets in and corrodes the connection and you get issues, unfortunately as corrosion travels back through the wires the strands become insulated from each other creating higher resistance in the wires reducing the current flow in the wires
Fitting MosFet Rectifier/Regulator helps and will improve battery life with it's faster internal switching plus it runs much cooler than the Shunt type, but it does not solve the underlying issue, Dielectric grease stops the corrosion, but doe not fix it and the only real solution is wire replacement, which is not the easy.