Ok. Seems they spec abundantly cautious. Of course they dont know what a specific installation will consist of and assume worst case scenario distances etc.
But given you limited shore input to 30A and even if operating at max inverter assist, total 47A. A camper size length of 10AWG could safely carry that current for duration until OCPD opens. 8 or 6AWG definitely will.
Given your output OCPD is about 12” away from the source, all conductors inside FMC, I dont think you have much to worry about.
3. Create and sell new products what are legislated thus assure consumer demand.
As an aside,
Its suspected such codes are sketched using charred bones, then signed to law with blood.
We all realise why codes exist...