Instead of changing the layouts of the 40+ playlists one by one, the easiest way to go about it would be to:
1. Create a new/empty playlist with the desired layout. So that means adding your virtual tags and appropriately sizing them (You'd be creating a template in other words)
2. Then go to the playlists folder in W-explorer and duplicate this playlist 40 times (much quicker than in MB). Doing this ensures that the duplicates all have the layout of the original.
3. Then return to MB and add files to the new playlists using the existing ones. e.g Selecting all tracks from old playlist xyz and adding them to one of the newly created playlists.
4. All that would be left is to delete old playlist xyz and rename the new playlist containing the files, xyz (name of the old).
You obviously would have to do this for the other 39 playlists (starting from step 3). But I reckon this is much quicker than changing/resizing the layouts for each of the existing playlists.
Also, if you would be dealing with auto-playlists too, you would need two templates...one for static playlists and the other for auto-playlists.
But it's ofc up to you if this is all worth the trouble