Is it possible to choose a value by the exec output pin?

Select node only has one exec input.

However, you can create a local variable, and use “set” on it for each exec node, and then merge the exec into the Add Relative Rotation, and have that pull from local variable, converted to float, converted to rotator.

Local variables only exist in functions, not event graphs, though. But you should be using functions for almost everything anyway, so that’s fine!