Another thing to consider is that it's usually 100%+20%, not 80%/20%. It's because you can do whatever you want to do with 20% time but that's usually not going

Another thing to consider is that it's usually 100%+20%, not 80%/20%. It's because you can do whatever you want to do with 20% time but that's usually not going to help your perf unless you can convince your director/org as well, not just a manager.