It's possible to modify most of an object's properties arbitrarily in a driver.
For example, the below driver, when placed on an object's X location transform, will copy that object's Y location to its Z location on every frame:
[0, self.location.__setitem__(2, self.location)]
Is there a known way to do the same when the property that is to be modified belongs to another driver?
E.G. The below code works to set the target of a variable on the driver of an object's X location when evaluated in the console, but not when evaluated in a driver on its rotation channel:
[setattr(self.animation_data.drivers.find('location', index=0).driver.variables["var"].targets, 'id', self),0][-1]