I read Sudsy's leaving was in part from him getting hit in the mouth by a hockey stick while out playing +-

This may be only partially true

attached is a picture of his lip busted open

I like Sudsy's character but at times he seems a bit un-natural how he shouts his lines (like he is just remembering the script) vs how well Ernie replaced him with much empathy playing the part

I do think the lines for Sudsy were written more smart alec than when Ernie replaced him

Never knew that.

I know the actor was back in a few later color episodes, playing a different role of course.