The suggestion about putting more battle related ground damage on Coruscant was one of the first I made on this thread and I was glad that RLM brought it up in his review.

There are a few things other than (or including) adding effects work that could be done.

Grievous is meant to be a master tactician and a formidable military leader but in the theatrical versions he comes across a very stupid comedy character (like most PT characters to be honest).

What if Grievous deliberately avoided damaging the capital not because of it's defenses but because of the division it would create with the Republic.

The Senate are safe in their chrome and crystal spires while the rest of the Galaxy burns.

This could be accomplished either by adding a line into the crawl or by replacing one of those unconvincing Senators and putting in a few new lines from a fresh actor expressing relief that breaking from this tactic has raised the Chancellor's popularity.

You could even have the Star Wars equivalent of a news real or newspaper swirl hologram where Palpatine after the battle says something like "I'm glad I was attacked. It makes me feel I can look the outer rim territories in the face".