Can I extend my 90-day tourist visa in Thailand or do I need to do a border run?

The original poster, after entering Thailand on a 60-day tourist visa and extending it for an additional 30 days, is seeking advice on whether they can extend their visa for another 30 days or if they need to leave the country for a border run. Responses indicate that extending the visa further is generally not possible, and a border run is necessary to re-enter Thailand for a new 60 days stamp. Recommendations include using a travel service for border runs and confirming the passport nationality for specific advice.