The fact that vpn solutions like battleping, wtfast, etc. can be used to get better results clearly indicates that the problem is not within SE's datacenter, but somewhere between your ISP and their datacenter.
Datacenter side problems, when they exist, show up regardless of if you use a vpn solution or not, and is up to SE to fix, but short of relocating the datacenter elsewhere, don't expect SE to be able to do much.