I personally don’t use the level blueprint much, but it needs to be handled in some way. But as long as that way is predictable and stable I do not think it would matter much if the level blueprint or some other particular part of level building is a bit clunky to use collaboratively. If you for example would not support more than one user editing a landscape at a time, it would still be very useful for many games.
As for the level blueprint, a message “XXX is currently editing the level blueprint” when trying to open it would be nice.