I get it, seen it many times. A question is asked and someone replies with a rant about trying Google 🤣🤣🤣 my opinion is just answer the question, if cannot just keep scrolling 🤷♂️
Either route, you'll not be converting to any 1 year visa. You'll simply be getting a 1 year extension to the visa your entered on. The fact that a legal firm doesn't seem to have the terminology correct raises a red flag 🤷♂️
Just use the sim you've been using as it sounds like you're happy enough with it, just top up every 30 days like you did when leaving for a few days and coming back. Only this time you're not leaving. And you get to keep your number, and LINE account if it's attached to that number