dragonxi
If your audience is global then I recommend using the US or DE nameservers. I do not recommend mixing NS regions. Choose one region only.
Instructions for setting your NS at Namecheap are available in Namecheap's documentation. You'll want to use the "Custom DNS" option: How to change DNS for a domain
All of our NS are running on the same type of system, so no individual NS is faster than the other.
The US name servers are located as follows:
- ns1.us.opalstack.com San Francisco, CA
- ns2.us.opalstack.com New York City, NY
- ns3.us.opalstack.com Dallas, TX
All of the DE NS are in Frankfurt.
All of the Singapore NS are in Singapore.
I don't know which VPS might be faster for 5G mobile users. Again, if your audience is global then I recommend using the US or DE nameservers.
ns1.us.opalstack.com is the nearest NS to San Francisco VPS.
You should get your VPS info within the next few hours.