The topic you pointed to (this one) did not actually seem to mention anywhere how much time is taken for autoscaling to kick in.
I did find this post by kurt mentioning “it needs to be maxed out 30-60s”. But maybe that information is outdated?
Ah, my mistake-- I’ll edit my post to make that correction 
I’ve been attempting to reproduce this issue, so having this information is super useful-- thanks for the quick response!