Seems to me that it would be much easier to trim the heather than move the sprinkler..

True but I am also wondering if moving the sprinkler back serves the garden better overall.

Why don't you first trim the heather and see how that works? Then if the rest of the garden still isn't getting enough water, have the sprinkler head moved, or add a head if necessary. Your irrigation company may have some advice on this too, so ask them what they think.

I would move the head since it is not watering properly if hidden under the heather

I am also on team move the sprinkler - we’ve done this several times over the years, it was a fast project and enables larger planted areas

Sprinkler company will be back Monday to fix a couple other things and this is for sure on my radar to discuss. But I think I will give it a bit of a trim today after work to see our starting point.

It does not sound as of you need to move the sprinkler or trim the plants. Just replace that head with one that pops up higher. Quite a few of ours are 18" pop-ups to clear taller plants.

We met with the sprinkler company yesterday and for sure need to move it. It is halfway into the plant.