With an inverter type generator I would NOT fit a Neutral - Earth bond without express recommendation from the manufacturer.
One way to check this would be to measure the Neutral / Earth voltage from the generator wiht no other loads connected. If this is ~50% of the nominal AC voltage, then it will be unsafe to fit a neutral ground bond.
Operation of RCD’s when on generator: possibly they will not operate, and just pushing the test button on the rcd will NOT test this - one would need an external tester. However, with a floating neutral/live setup, then a single fault (L/E, N/E) will not pose any risk, as there is no return path for the current. IF the generator is producing a biphase output, ground referenced, then the RCD’s will operate normally.