CMS Updating - Stuck on Step "Update all Videos with their real duration"

I found myself responsible for very old install of Xibo CMS (1.7.9 I think) running on an equally old version of FreeBSD. I am going through the upgrade process to 1.8, but the updater is stuck on step# 104, version 1.8.0-alpha2, Update all Videos with their real duration. I can start the process, and it looks like php-fpm is running with CPU usage for a while (up to an hour I’ve been able to catch), but then it will just stop and the update page never completes.
This installation is heavily used and not well maintained. It has a data store of 900GB and hundreds (maybe thousands) of images and videos.
Is there any way I can either manually clean up some of the old files so they are not bogging down the updater, or skip this step if it is maybe not critical to running the CMS?