SP4: Cron performance when modifying a time based publishing and a break ACL inheritance on sections of 750 pages.

I imported (and validated) a 3'000 pages web site that I replicated on another site (in no workflow). This process runs all the nighty (every 30 minutes).

This morning, I broke all ACL inheritance on a section of 750 pages and I put a start and edn date to another section of 750 pages (cf parent JIRA).

When the next cron occurs this is taken dozens of minutes to replicate those two changes (an inherited TPB and a single ACL break inheritance). The export file took about 15 minutes to be created and imported on the destination site (cf screenshot 2 with the time of creation of the last file).

This is now 10:56 (cron started at 10:30) and my CPU is still continuing to heavily work.

Are we detecting correctly such modifications of properties which are then inherited on sub-objects... in order to avoid havng to reimport thousands of objects because of a single change on a single container (in fact two container because of two containers' sections in this case)?