Prototyping with a very small surface mount connector/socket
When having to use connectors like these, and the associated high tech parts that tend to be used with them, it is often advisable to rethink and re-define what prototyping actually means. I would suggest that rather than get hung up on breakout boards that you consider a first pass at your circuit board design to be your prototype. Use all the part footprints that are for the target parts for your assembly. Feel free to add what ever additional test access connections and debug hardware as required to this initial design. This approach has many advantages including a main one that it puts the parts into the actual configuration they will be for your final product so that you are testing something real as opposed to debugging ghost problems on some cobbled together "quick setup".