At close of day I may have a collection of files for the current tasks in hand open in UE. When I open UE next day those files are reopened (if the appropriate Config>File Handling>Load option is selected). That's great.
Where it goes wrong is if before I've started UE I click to open a file somewhere on the PC and it is of a type where the default program is UE.
In that case UE opens with just that file, having "lost" the files I was working on before. By ancient and befuddled brain lets me down and I can't always remember where I left off. The random and varied nature of my work means "projects/workspace" is seldom appropriate. I can usually jog my memory and reopen the relevant files using the "recent files" list.

A better option might be if UE were to have a startup dialogue box "Reopen last-used files?".

All needed to get what you want is already included in UltraEdit.

UltraEdit starts with loading the double clicked file and additionally the files remembered on last exit if the configuration setting Open from Explorer also loads file list is enabled at Advanced - Configuration - File Handling - Advanced.

There is also an alternative. Configure UltraEdit as follows:

• File Handling - Load: Reload files previously open on startup enabled
• File Handling - Advanced: Open from Explorer also loads file list disabled
• File Handling - Advanced: Save project information for use on multiple systems enabled
• File Handling - Miscellaneous: Close all files when opening or switching projects disabled
• Application Layout - Miscellaneous: Files selected in explorer will open in a new single instance disabled

Next create with Project - New Project/Workspace a new workspace best with a name like Last Workspace stored in the directory %appdata%\IDMComp\UltraEdit. You don't need to add any files because you use it just as workspace and not as project.

The currently opened files of this workspace are now remembered on closing the workspace or on closing UltraEdit while workspace is open in the file %appdata%\IDMComp\UltraEdit\Last Workspace.pui. On exit UltraEdit remembers that this workspace was open on exit and therefore reloads it when UltraEdit is started without any file on the command line.

But if UltraEdit is started with a file name on the command line (what Explorer does when you double click on a file associated with UltraEdit), UltraEdit loads just this file. You can now decide to simply edit this file and exit UltraEdit (with remembering this file in uedit32.ini), or additionally load the last used workspace with clicking on Last Workspace at bottom of menu Project.

Of course when just editing the opened file and exit UltraEdit, this file is remembered in uedit32.ini and not the workspace. So on next start of UE this single file is reloaded, but you can at any time open additionally the Last Workspace from project menu. Exiting UltraEdit with the workspace open results in remembering all opened files in Last Workspace.pui and reloading this file list on next start of UltraEdit without a file name on the command line after Windows reboot.

A third variant would be to have Reload files previously open on startup also disabled resulting in never reloading files automatically and instead use the workspace file whenever you want to continue on a set of files you last time worked on with adding currently opened files to this workspace on opening the workspace.

Summary: You can use uedit32.ini as workspace file or alternatively use a real workspace file with or without automatic reloading.