This is such a poorly designed change. I understand you might believe spellqueuing unintuitive, but it really is as simple as pressing your next spell on time so you don’t have a gap. Most people probably do it without thinking. Additionally, you’ve now made it more convoluted by making nether precision double dip, but not burden of power. The solution is not to remove nether precision double dipping because that makes the rotation completely unfun, comprised of only Missiles → Blast → Blast loops.
Sunfury arcane needed a targeted nerf. It was doing too much damage, while spellslinger was in line with other specs/classes. But this entirely changes the way sunfury arcane is going to play rotationally, which was very fun and the reason mages rioted over the previous change that removed double dipping nether precision. We don’t want to spam arcane blast, and the rotation is very close to that. You’ve now removed the second double dipping interaction that made the rotation work, a week before raid comes out. Please revert the change, and consider nerfing the damage from burden or the amp from spellfire spheres.
To those that chose to play arcane because it was actually fun, that’s (probably) gone. To those that chose arcane because of the damage, well they should’ve known that would have been nerfed heavily.