The spot shadow settings do not even affect anything in the actual match, they just affects how legends look in the picking screen. So there is no way it can fix anything (or make it worse for that matter).
I had those settings disabled for a long time now and they do not help at all with the issues described in this thread. Unfortunately, there is a lot of false and illogical info being spread around...
Read the post of @rump_jaeger above, it is the only meaningful and logical post in regards what can be going on.
The launch option that is being mentioned configures some simple settings (e.g. vsync, monitor refresh rate, disables intro video, etc.; so I don't go through all of them) that cannot and will not fix the freezing/crashing issue.
Some people here apply these 'fixes' and then merely get some luckier games where they don't freeze or don't freeze so often and then they attribute it to the 'fixes'.
In reality they just landed in a different spot and traversed the map in a different way so that they inadvertently avoided the buggy/troublesome areas or the sequence of events within the game engine was different and did not lead to the bug that often.
The ball is is the Respawn's hands. Sadly, they are not competent enough in providing a fix or an apology, both of which were due few days ago...