I actually don’t remember being annoyed by this for a while now which means it hasn’t happened to me in as long. I’m prepped for the disapproval, but I very rarely shut down my laptop and close my Designer down, and I do use the search/filter box in the project browser occasionally.
I do have something else to add though, and that is that regarding an embedded SVG which has a bad quality on one of its bindings on a nested element’s prop value (or most likely any structure of nested dictionaries and arrays). When you fix the bad quality binding, the whole prop tree structure collapses. That I can produce every time and is very annoying, especially when you might have 4-5 nest levels of elements and then you have to remember which array indices you had expanded.
Funny that in the linked thread you complained that IT had forced a reboot and that had lessened the occurrences.
I go weeks at a time just suspending and resuming my laptop (home => office => home). My permanent VPN routes between home and office, so open designers pointed at office VMs or local VMs just reconnect and keep working.
I usually reboot only for new kernels.
Haha, that doesn’t stop the stubbornness from continuing though! Also, it’s a waste of time having to reopen everything again 
Sorry if I’m late to the party.
I still have this issue and in my particular case it’s not connected to the use of the search/filter box. I’ve just tested it: opened the Designer, browsed to a pretty deeply nested view and the tree collapsed itself.
Alright, well, we had hoped we'd isolated a root cause being related to that search/filter box, but apparently not. Either way, we'll push those changes (probably in 8.1.21) and keep trying to figure out the core issue.