I have a multi-project release (call it 2.0) where I want to include heterogeneous collections of releases from various projects.
Let's say I have project A and their 2.0 release works.
I also have project B and they are 2.0 and then due to some bugs a 2.0.1.
I also have a project C and they split their work between 1.5 and 2.0.
I want to create a CPR to include A-2.0, B-2.0, B-2.0.1, C-1.5 and C-2.0. https://community.atlassian.com/t5/Jira-questions/How-do-I-add-more-than-1-release-per-project-to-a-Cross-Project/qaq-p/618119 accepted their own answer with "JIRA is not set up for this" but why can Portfolio, as a JIRA overlay, not do this?
Essentially, this would be a "quick filter" that avoids having to individually select the correct linked release filters over and over again. The custom CPR field can be set in all those releases and Portfolio already has the capability to filter for multiple releases within disparate projects.