I tested adding a stack file "ForTestLc810_001" to ForTestLc810_000 in standalone setting
1. Stack "ForTestLc810_001" doesn't appear on list but it appears on project browser
2. After a restart of livecode, stack file in standalone setting there is a stack "staqck" in "Stack files in the application" list and a "untitled 2" in "stacks in the selected stack file" list. ForTestLc810_000 and ForTestLc810_001 appear on project browser.

Best regards
Jean-Marc