"One thing or another" is singular or plural?

Question

There are a lot of answers about has/have but I couldn't find one that answers my question.

Which one is correct ?

Window size or position has been modified

Window size or position have been modified

I guess that if the or was exclusive I should use has. But there, the window size and position can be both modified at the same time.

Thank you.

Answer 1

In this case, you would take the "maximum". Just like math, you can develop -> size, position, size and position.

As there is a possible 'and' (plural), this is the correct grammar:

have been modified