AC 500 50 amp question

Bluetti your input please…
using two of your future 50 amp units sharing feeds for a panel >>>

  1. there is no potential difference on what you would consider the “neutral” side and they can be Siamese together without issues?
  2. guessing these will be floating neutrals how will you address the neutrals with respect to the NEC and grounding at the first means of disconnect?
    Thanks in advance