Overtime

Hi…..here is our situation.

We have a salaried employee who normally works 37.5 hours per week (9-5, with 30 minutes for lunch). He is a customer service manager but does not have direct reports so no managerial duties. He is sometimes required to travel and conduct training sessions at trade shows on Saturdays and Sundays.
Occasional weekend work is a requirement of the job. He would be entitled to overtime pay or time off in lieu after 44 hours worked, correct? It doesn’t matter if his contract stipulates additional hours are required to fulfill the role, correct? He would not be exempt from overtime because it is not a sales position, correct? Saying it’s a requirement of the job doesn’t shield us from having to pay overtime or provide time in lieu, correct?
And offering him an additional week of paid vacation wouldn’t prevent us from paying overtime or providing time off in lieu, correct? Because he could accumulate more than 5 additional days off in lieu and therefore we wouldn’t be meeting overtime requirements.