How can you make an applescript display dialog window be the front-most window

In Sonoma 14.7.4, the AppleScript display dialog is not topmost in the window display hierarchy and will be occluded by the frontmost application. There is no AppleScript solution to avoid this on Sonoma short of writing your own display or alert window in AppleScript/Objective-C and using the window level constant NSFloatingWindowLevel to force that window above all other windows.

In macOS Sequoia, a standard AppleScript display dialog window remains above all other windows by default.

It could very well be that the Apple developers supporting AppleScript finally woke up in Sequoia and realized that they weren't setting the NSWindow object's level to NSFloatingWindowLevel to force the display dialog to be topmost. One line of added or changed code to fix this level issue.

Same reason that if you opened a scanned (but not OCR'd PDF) in Apple's Preview in Sonoma, and chose the Export… option, you would see for the first time, an Embed Text option. Selecting that and saving the exported PDF would OCR the PDF text to enable text searches in the PDF. Apple enhanced that further in Sequoia. Apple never told the user community that beginning with Sonoma, they added this (by another name) OCR feature to Preview.