Hiya @shabash 👋
ATO administers super guarantee obligations, which, as you've stated, is calculated on OTE up to the maximum contribution base. Amounts calculated in excess of that are not super guarantee. That's where the ATO jurisdiction ends. ATO doesn't control what you choose to pay your employees. 😉
They do require employers to report RESC for super contributions controlled by the employee, so if you gave your employee a choice about the excess to be paid as super or salary and they chose super, that would be reported as RESC. If they choose salary or the employer chooses salary, you just report the gross.
Deanne