Yes, sure, it's a one-liner:
CoronaRenderer.CoronaFp.startInteractive()
As a macro (assign to keyboard or button):
macroScript CoronaStartIR
category:"YourCategoryGoesHere"
toolTip:"Start Corona IR"
(
on execute do (
CoronaRenderer.CoronaFp.startInteractive()
)
on isEnabled do (
return hasproperty renderers.current "meta_coronaVersion"
)
)
Save as -for example- "CoronaStartIR.mcr" in your usermacros directory, then assign it in Customize -> Customize User Interface.
Exposing Corona toolbar buttons was requested many times btw., I assume it will be done.
Good Luck