I've seen a bunch of timeouts / heartbeat / keep alive durations. I think it might have been Wireguard, but 25 seconds seems like a good number. Usefully long, most things that break are more likely to do it at ~30 seconds, and if there's an active activity push at 15 or 20 seconds with device wakeup then the keep alive / connection kill might not even happen.
Full Refresh; yes please, in the protocol, with a user button, with local client state cached client code and reloaded state on reconnect. Maybe even a configurable polling period; some services might offer shorter poll as a reason to pay for a higher tier account.
If the user ever has to push a "retry" button, the networking levels are very badly designed. Just because some crappy web sites work that way does not mean it's OK.
The user shouldn't _have_ to. However, a 'refresh state' (and validate state, more gracefully than a full kill and reload) button can be both helpful and psychologically reassuring.
It can also be very helpful for out of band issues, like ISP hiccups, random hardware failures, bitflips, etc.
Full Refresh; yes please, in the protocol, with a user button, with local client state cached client code and reloaded state on reconnect. Maybe even a configurable polling period; some services might offer shorter poll as a reason to pay for a higher tier account.