I don't even see how a trial makes sense unless it is well signposted to passengers - isn't business class check in towards the south of the terminal, and while the stairs/escalators are towards the centre, it needs to be communicated clearly to affected passengers to have any hope of success. I can't see how that will be the case in a trial.

Does the split of passengers actually work so that neither lounge is overloaded?

I can see a long-term benefit in upgrading the pre-flight service for Club World passengers (although I'm not sure what happens to a silver guesting someone while travelling in Club World...) and using a segmented product to do this, but that then calls into question how much better the service will be than in the Flounge for Gold passengers, who've gone through the First Wing...