Developer account associated region.
No, you cannot change region associated with your developer account.
Your developer account is based on the country from which it was created, regardless of your current geolocation. You can only install public channels distributed in the Channel Store associated with the region of your account. Using a VPN of another country will not allow you access to a foreign channel.
If you'd like to test your channel in a region where you do not reside, we recommend setting up a new Roku account while under a country Y VPN to test the production channel (making sure your laptop is on country Y VPN). That's the easiest way to test out your production channel to see how it performs in country Y.