Right - so in Chrome's case then Google using QUIC as an in-app service is probably fine, as indeed, I trust Google to ship fixes and updates much faster than Microsoft. Also it's far more likely that enterprises have Windows Updates blocked or delayed than Chrome updates - and with Microsoft updates you have to wait for Patch Tuesday every month unless it's something really bad.

My point still stands though, that if you aren't prepared to support an "evergreen" software product for the life of your users, then you should still support OS-provided services, even if you do have your own QUIC support baked-in to your product.

I agree that for updatability it should be something that can be shutdown, reloaded, restarted as simply and with least risk possible. Now I'm thinking that it'll be easier to checkpoint/restore a quic connection than any other thing based on tcp or hidden in the kernel, so you could even do zero-downtime update.