No luck with 4.16.
Given what Chris Babcock said above, I feel I may be missing something easy(like a mobile specific setting for substepping) but as it stands I’ve not got working substepping on mobile, or at least the physics seems that way.
I’ve gotten distracted by making my game work well on desktop, doing tasks that are vital for release and not looked into this as much as I should have.
Will report back when I have a deeper look (unless someone else comes up with a definitive answer first)