It doesn't look like ppk is in the Nordic github, so leaving this here:
On linux, ppk v1.0 work great, but v1.1 hangs and takes forever to draw the windows. I traced the problem to the logging thread, do_logging() is a tight loop that does nothing between update_log's. I changed self.update_log to a threading.Lock that gets acquired by the do_logging() thread and released by the rtt_handler and that seems to have fixed it.