I think the idea of having a separate technical score and performance score for each dance would be a logical and very easy change to implement. The 50/50 split stays the same, but the judges have more numbers to work with and can put a greater distinction in scoring the dances. That way, for example, a Bobby freestyle doesn't get the same score as a Milo or Evanna freestyle, even if the judges were thoroughly entertained.
It also allows for more specific acknowledgement of what the couple did well and what was not done well...Len's dislike for lack of content and "messing about" and CAI's "lift police" could factor into the technical score. Things like "you were thinking about the steps," "it was too careful," and "lack of chemistry" would go into the performance score.
If anything, it would give us all more to talk about!
I can't imagine it taking more effort than, for instance, when they had a 4th judge's score to add in or when the couples are each dancing twice in the show and get two sets of scores. They have done it on the show before...what was the problem that they had to get rid of it?