Look into portable monitors if you want to travel with it.

If you want to stay in Japan and keep freelancing check for self sponsorship of visa.

I think just getting eSIMs would be much cheaper tbh. I get that it can be annoying to have to shop around, but services like Airalo have tons different countries you can chose for https://www.airalo.com/ You just need to set up an account once and then get an eSIM for the country you need through their app.