I'm using tk2dStaticSpriteBatcher to batch a bunch of 'block' object into a collection of block objects. It looks like this:

As you can see, this batched sprite is comprised of many edge colliders.
Due to the way some other parts of my game works I need the object to have just 1 edge collider surrounding just the 'actual' edges of the object, like this:

I made that collider myself, as you can see it's pretty rough and takes a long time to edit manually by shift-clicking the collider vertices into place.
I realise tk2d doesn't really have any feature to do this, but I was wondering if you might be able to suggest some options I could try?
Thanks!