Speaking of layers in TRS22:
In TRS22+ which I have (so I don't know if it's true for TRS22 regular), there is a bug that you should be aware of. If you have the route layer selected as the layer you want to put objects and splines on, and you go to Surveyor 2.0, when you return to Classic the chosen layer will be session, without warning. Of course this means that any objects or splines added after you return to Classic will be on the session layer. I reported this bug several days but was told it had already been reported, which is good. As of the latest build of TRS22+ (117297) this has not yet been fixed. For most users this will not be a problem unless you have multiple sessions, and a merge of session stuff to route layer should fix it. However, if you are not saving the session routinely, be aware of potential problems.
Why would someone not save the session routinely? It has to do with UDS. If you want to preserve the original start position of trains, the advice is to not save the session, since the current location of trains is stored in the session. This advice along with the layer bug got me into trouble.