Is there a variant of 溏 without the 口 component that's used in Taiwan?
焿 is a character on its own.

ZDic：http://www.zdic.net/z/1d/js/713F.htm


  gēng
  〔～子寮湾〕地名。在中国台湾省东北海岸。


Wiktionary: https://zh.wiktionary.org/zh-hans/%E7%84%BF


  “焿”是“羹”的异体字，为台湾本地自创的形声俗字。


羹 means '(thick) soup, broth'.