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Even easier, and something I found out rather belatedly. Open the session associated with the route and do a save-as. When that's done, there's the option to save both the route and session under your username. This will preserve any session that's associated with the route plus the route that you can edit. You can even rename the route and session too at that point, so use that to make the necessary changes such as putting in your initials or something else to differentiate this route from the original.
The warnings won't prevent the asset from working. Most assets with a build version below 3.5 will have this type of warning.