Scheduled loops using same function
It is a simple schedular. It only changes to another task when yield() is called. The delay() function uses yield() and a lot of code and libraries use delay().
That means that if you code does not contain a delay() then you need to call delay() or yield() now and then, or other tasks will never execute.
It is probably safe to use the same function, but every time a delay() is used, an other task could run or another task will continue from there.