I’ve been playing around with and modifying your macro. I would share but don’t know how to post the short form and don’t want to mess up this thread. Keep in mind I’m new to fire mage but I wanted more control in fire blast so I took out the autocast and added it to a ctrl mod. I also added flamestrike to shift and use it for instacast for groups.
How i’ve been using it is open up with the macro which cast fireball. Combustion will make your first fireball crit, then you move & cast back and forth casting scorch with combustion active as it has a shorter cast time. So you get a bunch of crits and combustion is done, then I stay still casting fireballs and as soon as it crits I press control to fireblast and then alt for the pyro.
It does give you a little more crit sustain than your version, but your also working a little harder.
PS: Like you I got a sound on weak aura that does the boxing ring ding everytime the pryo/flamestrike is instacast.