In all cases we are now using Ancor Marine grade/type wiring in our builds or repairs.  For both 110VAC and 12VDC circuits.

Ancor Marine grade is manufactured with high quality tinned stranded wire for extra strength.  Tinning inhibits tarnishing and oxidation commonly found with solid copper conductors.

Anchor Marine grade has a flexible polyvinyl chloride (PVC) jacket to further add to its durability.  It is coated to resist the harsh effects of heat, abrasion, salt water, battery acid, gasoline, and UV light.

We stopped using, or recommending, Romex type residential  stiff solid copper wire, when running 110VAC circuits.

In addition to using Ancor Marine grade wire.  The wire ends are terminated using appropriate terminal lugs that are crimped with an appropriate crimper, then soldered, and heat shrunk.  The terminals are then attached to their designated receptacle or terminal strip, all using screw down points.

Ancor Marine cable has been used on boats for years to eliminate vibration and stress due to flexing.  All issues associated with stiffer wire types.  The crimped and soldered ends also help prevent loose connections, arcing, problematic power issues, and lessen the potential of electrical related fires.

Yes it is more expensive.

Below is a simplified configuration.
Integrating both 12VDC & 110VAC