Wavelab 11 backwards compatibility

Any chance there could be a “save as old montage” option? There are many reasons why this would be useful. Being able to open a montage done in WL11 at a studio that hasn’t upgraded, for example. Plus, during these first months, I’d feel a lot more comfortable migrating to 11 if I knew I could revert back to my trusted version to continue the project if problems arise… Of course, I understand certain things would be lost de pending on what version of WL you would revert to…

Sorry, no. But remember that when opening a WaveLab <= 10 version, this one is not modified, and a copy is created. Hence you can still use that old version.
But if you do edits in WaveLab 11, there is no way to only export a compatible version.