Atm, we are seeing errors on the client and people are left to making guesses as to what the problem is because we have little or no client-side logging that we can easily turn on. Having good client-side logging will help people to unblock themselves a lot better Vs waiting for someone else to come along to debug the system to tell them what's really happening. I bet it will also leading to us creating fewer and more accurate JIRAs.
E.g. would be nice if we could turn on logging of SSE events to help diagnose page refresh issues etc.
Things to look at for usage/inspiration:
Would also be nice if we had a Developer extension for Chrome that could be used to switch on different logging categories.