A way to access an "emergency button" function is a significantly smaller sin than arbitrary crashes.

I question that. I would expect in most cases that even if you manage to free up some memory you only have a little bit longer to run before something else uses all the memory and you are back to the original out of memory problem but no place to free up more. Not to mention those caches you just cleared should exist for a good reason and so your program is running slower in the mean time.

What if for my program, 99.99% of OOM crashes are preventable by simply running a GC cycle?