There were many threads about shortening the duration of one's bond funds back in March and April. Many folks reported that they had shortened their durations including posters with over 10,000 posts. That was rather telling.
I think it is too late to shorten duration. Intermediate-term bond funds have dropped more than they should have and they will recover somewhat in the next few weeks. You might ask your question in a few weeks. In the mean-time, it might be time to buy more intermediate-term bonds while they are oversold in anticipation of the rise they will have and then after the gain, sell the funds.
Unfortunately, the money used to buy those funds has to come from somewhere and may not be available. For example, if one has extra money, maybe they want to use it to buy equities instead.
It might just be best to sit pat.
It's all about market timing, uh, I mean rebalancing, uh, I mean opportunistic rebalancing, uh, I mean short-term opportunistic rebalancing due to a short-term change in one's asset allocation.