It seems fine so far, and while it's hard to tell for sure, I don't think 256 vs 128 has a noticeable impact on CPU.
The whole problem I was trying to solve above was unrelated to it specifically (I hadn't even tried it yet). When I asked about 2.9.2 in the other thread, it was when I thought you were successful modifying server.conf in the beta (it turns out that you were still talking about the client). So if you were also successful in doing that in 2.9.2, which is the version that I had been testing with, then I would know that I had some other problem.