This update did not significantly affect XP rates. Fletching can be practiced when you're slaying. You can run while flying. To make the incredibly low rate of XP for Agility and Runecrafting bearable, you could fly. It's now impossible to flych more than one set (10 bolts and 15 Arrows) in 0.6 seconds. In the past it was possible to flytch 2 or 3 sets per game click. This raised the XP rates of flying bolts over Magic Longbows.
A nerf can be a problem However, Bolt fletching was hit twice in one update. What positive "upgrade" do we get in exchange? Semi-afk train: Some people prefer efficiency with greater exertion. Why should people who put in more time in training be punished for it? Jagex encourages laziness.
Learning multiple skills at the same time is more effective than focusing on one at a time. If you believe that only one skill should be taught one at one time will likely be a bit hesitant at a bank and wonder why it is so slow and boring. Or, they believe that training multiple abilities at the same time includes, for instance fishing, and then making use of the fish that is caught for cooking.
It's not against the rules, or the nature of the game to work in multiple areas of skill at once. Zarfot was famous for his training expertise and 200M Fletching.
You can't learn any other ability while studying it. Alching is a close match, but it is restricted by the Standard spellbook. Ourania Teleport isn't available, nor is casting using the Monkey form. Also, there is no casting in Ourania.
Want to learn more about RuneScape gold at https://www.rsgoldfast.com