Italian Meringue with Non-Simple Syrup?
Have you tried looking for strawberry compound? The only issue perhaps with cooking the strained strawberry juice is that the flavour might become less intense! This could easily be fixed by putting strawberry jam or compound inside the macaron alongside whatever other filling you are going to put in it.

Strawberry compound is awesome, a ton of flavour in a very small amount, so it is perfect for applications where you don't necessarily want to incorporate too much additional liquid. But I do think it is a 'specialty' product. I have never seen it in a store (even specialty), you would probably need access to a good supplier or go online. Worth it though. 

On second thought, there are usually 'essential oils' or natural flavouring, I am sure there is strawberry - which would be effective to add to your meringue during last whip. Add some food colour as well, and voila!