The PoW and some degree randomized PoS blockchain is immune to split-world attack. So someone may ask if so why still some government may want to mess with bootstrapping? the answer is to redirect their citizens to malicious nodes and that nodes would associate their usernames (wallets) with clients IP address.
solution:
1- we have a PoW blockchain (bootstrapping blockchain) that full/RPC nodes stores their (ddns) domain address and PGP/SSL keys.
Mining on this blockchain is rewarded.
2- Client download this blockchain and select one/multiple node and try to connect to them
3- What if ddns or ISP/vpn service provider acts maliciously and block safe node?
the client before logging in to its wallet/username on main blockchain) login to wallet of the bootstrapping blockchain and report the down node incident including VPN/ISP used to bootstrapping blockchain (these reporting should cost users to avoid spam reports)
the accused node have time limit to post a reply to that blockchain that it was online and ddns/vpn was responsible.
The user will try another VPN and this also would be a bad reputation for that VPN
Similar happens for ddns provider if it was its fault
The reason nodes IP is not listed in blockchain is too keep blockchain as small as possible when (we dealing with nodes with dynamic IP address). This way mobile device can download blockchain directly. cellphone see how fast miners answers to determine if the answer come from international network. Other option maybe if the bootstrapping blockchain be a randomized PoS, cell phones also can involve in validation (fake minted reward will be shown themselves when receiver try to use it so it)
To keep mining continue clients can sent random number to a temporary block. Miners would have to mine combined checksum of bootstrapping blockchain and this temporary block
Option B
Nodes store their IP address instead of ddns address in bootstrapping blockchain
if this blockchain got big. light wallets can randomly select a position in bootstrapping blockchain and the server, the light wallet relies on, provides that position data, node IP address + PGP key and merkle tree proof (I don't know if merkle tree proof is a "position proof", too or not, but probably if the client ask for multiple positions in bootstrapping blockchain it would be safe enough)
Incidents reports and nodes replay can be stored in separate blockchain so the bootstrapping blockchain from time to time can even rebuilt if it became full of dead IP addresses