My issue with the lobby size being 7 was that as someone who mainly plays Cav, there were barely any traces to be found. Her expertise is the most effective during phase 1, and the lower lobby size means very little traces - which in my opinion, makes her almost completely redundant. On smaller maps, I combatted this by placing expertise cooldown on blue chip or higher. However, on Fragrant Shore which is the most extensive map, even with my expertise cooldown on purple, I could only get 2 to 3 traces by the time the vault was open. On the other maps, I would get about 3 to 4 traces most of the time.
This brings me to my next issue - one thing I noticed is that either all terminals would be done within a VERY short amount of time, or none at all. The issue obviously does not lie purely due to the lobby size, but I do think it contributed. Again, as someone who plays mainly Cav, this means that due to the terminals being done so fast, everyone was rushing to the vault, rendering Cav's expertises practically useless. Or, when no terminals were done, it meant that players were doing nothing or very little - again, meaning no traces were left to be found.
Did I win as Cav during this experimental weekend? Yes, I did. But I don't think her expertises helped me very much in the majority of the games won.