In my experience, I've seen noticeably more STIs experience ringland failure than WRXs. As far as the tune, you nailed it when you said it's a catch 22. I personally plan on keeping my WRX far past the weak-ass warranty period, so dropping a safer tune was a no-brainer for me. Knowing my luck, I'd run the stock tune for 3 year/ 36,000 miles, THEN have a ringland failure and lose my money anyways. No thanks. I have zero regrets I did my tune immediately.