I don’t think any FX work would even need to be done for the short few shots as Yoda is attacked by clones. We can see that there are two wookiees talking, but there’s extremely little there to indicate one of them is Chewbacca.
I do want to point out that I am still hoping to come across a suitable line for 3PO to replace “I’m beginning to get the hang of this flying business.” I thought his line about “poor little R2” getting into trouble from the AOTC droid factory would work, but there’s machinery audible throughout.