Adding new rSeries Tenant to existing Device Group

We are also refreshing our iSeries with rSeries hardware.  We are going to add the new devices to the current HA group to get the configuration synced on this weekend. Although we have only common partition. Please share your experience with config sync if already done or going to do it sooner. We already ran into an issue in our earlier attempt described in the article. Make sure you don't have a HA-sync certificate expired already. 

https://my.f5.com/manage/s/article/K41500200