I can't find anyone who has described this exact issue, so I thought it was worth sharing. When I first get in the car, I follow the process learned on here: foot on brake, press start, and then don't dare touch anything for at least 60 seconds or so, at which point I feel safe to touch the "agree" button. Then I slowly, and patiently, scroll through each of the screens in order to "buffer" the page, so to speak, and the delay is almost non-existent from that point forward. Then I turn the bluetooth on for my phone, and verify that it is connected. At this point I am good to go. The problem I notice, is that once I stop the car (foot on brake, push start button again), even if I don't get out, open the doors, or anything of that nature, once I push start again, the bluetooth will not connect. Well, it "shows" to be connected (the little phone thingy turns green) but if it rings, all I hear is the phone itself. Pushing "phone" on the steering wheel does nothing. The only way to get it back is to turn off the bluetooth on the phone, wait a few moments, and then turn it back on. It again works, but still, it's a hassle.
Sorry to be so long-winded, but the more explanation, the better, right? It could be covered in the upcoming 6.15, but hey, you never know.