What would be ideal for me is to be able to hold F and click another enemy at any time to make it so the next swing seamlessly targets them. The way it currently is, doing this gives mixed to poor results if you're standing still. I've been testing this on 2 infinite health stationary targets spawned right next to each other, and what I found is if you hold F and spam click the other enemy, you won't switch until after a seemingly random amount of swings (although I can only assume it depends on when in the swinging animation you click on them.) Sometimes I changed target instantly, but other times it took up to 10 swings. This can be very frustrating sometimes, such as when trying to cycle between multiple spiders to keep them all stunlocked. Attacking by holding left click instead of using F is better but still not perfect, with the character sometimes inexplicably stopping for a second and doing nothing before switching targets even though I'm still spamming left click.
Attack a target continuously then try to switch to another target while standing still.