I like to put the value (usually a symbol) in the project name, but it works the same if the value is in the notes of the project or in the name of a tag on the project (and the same applies to parent action groups).
My workflow using markers in item names: https://discourse-test.omnigroup.com/t/two-of3-perspectives-puzzlers/43399
People using tags: https://discourse-test.omnigroup.com/t/best-way-to-prioritize-projects-and-actions-in-omnifocus-in-2020/51270
People using text notes: https://discourse-test.omnigroup.com/t/need-help-w-a-custom-perspective/52412
Yes, I’ve noticed that the refresh of the perspectives which use the text-search rule isn’t always immediate, especially when removing the text string like you described. I’ve never restarted OF for this though. I’m not sure exactly which conditions trigger a refresh, but I’ve been able to obtain it by closing the OF window/tab and opening the perspective in a new one.
Thanks for sharing the response from the support team. If they implemented both changes simultaneously, there would be no loss of functionality (even originally unintended).
To be able to reproduce the behaviour that I and others currently rely on, the new rule would need to be “Has a parent which matches search terms:”, where ‘a parent’ could be the project or a parent action group (they could even extend this to folder names for additional superpowers!), and matching in tag names or notes text continues to apply.