Automatically Soft Credit this Organization for Gifts - Backdating Soft Credit?

Hi, everyone -

We went live on RENXT last year and are now interested in selectively utilizing the checkbox on Org Relationships > General 2 tab which allows for soft crediting a parent organization for any gifts made by its subsidiaries (at least, that's how we would use it). However, according to KB article 48273, this checkbox only begins adding soft credit going forward, and since many of our org records already have gifts on them, checking this box won't get us a total recognition credit on the parent org. In fact, it seems like it might be worse to check this than not, since when the time comes to calculate total recognition credit for an honor roll, we won't know exactly when that checkbox was checked, and so what the cutoff was for included soft credit vs. soft credit we still need to add in manually. Has anyone else dealt with this, and if so, how? One possibility is to go back and add soft credit to each existing transaction on the subsidiary to the parent org, but in many cases, that is a lot of gifts. I wondered if there might be a plugin to expedite this process, but I didn't see anything. What experiences/suggestions do you all have with this issue?

Many thanks in advance for your assistance!