Much easier to drop some router on site that is telco neutral and connect back to your telco neutral dc/hq.
Much easier to drop some router on site that is telco neutral and connect back to your telco neutral dc/hq.
May as well pick a single solution that works across all Internet connections and weird setups, be an expert in that, vs having to manage varying network approaches based on telco presence, local network equipment, operating country, etc.
(btw, have you actually read past the first 7 words? I'm much more interested what people think about the latter parts.)
Need to provide support access to 10k-50k locations all with the same subnet (industry standard equipment where the vendor mandates specific IP addressing, for better or worse). They are always feeding in data into the core too.
Much easier to just VPN+NAT.
I'd probably use the IPv6 + NAT64 setup in your situation.