hi @JP_atNYU
Welcome to the community! The show summary function creates a new column in the parent items which is a special type of mirror column. Although the function to summarize to parent is great, you can’t do much with that special column. It can’t be used in automations, nor can it be used to hold information if there are no subitems.
That is why we created an app called Rollup Subitems. It rolls up the subitem column to a parent using normal monday columns. See also Use Mirroring With Automation - #55 by basdebruin and Merged mirror columns for items with no subtasks - #5 by basdebruin.
MJore details of this app can be found here: 25|Rollup Subitems - Excellent Team The documentation and screenshots are work in progress 