> Would it have made sense to deploy a "sacrificial lamb" (mocked up mirrors with damage measurement mechanism) to the chosen lagrange point

Probably not. Getting there is _hard_ and expensive all on its own.

> I am underwhelmed by the photos.

That's unfortunate for you. I have a hard time imagining the frame of mind where that'd be possible.

> Presumably there will be significant scientific benefit beyond galaxy porn?

Yes, there is benefit beyond the pictures being pretty. The galaxies we're seeing are older and more detailed than ever before and contain a bunch of new data to work out models of the universe.