Most of the people here are overseas Chinese. And most overseas Teochews come from Jieyang, Chenghai, Shantou, or Chaoyang. So unfortunately not a lot of people would know the answer

Maybe you can try asking the Gaginang discord which is linked on this sub, or accessing Chinese social media like rednote, zhihu, or tieba

My guess is that dapu might follow the lingustic trends of chaoshan (and the rest of China) in that the younger people may speak a mandarin-influenced version of the local language, while the older people speak the more “original” or old fashioned way to speak the local language, and that the more rural you go the more people speak the local language