Findings from more recent HK dictionaries (in chronological order):
粵音檢索漢語字典 (2006.12) – sim6
中華新字典 (2007.1) – sim6 (standard), sin6 (variant)
商務新詞典 (2008.1) – sim6
中文新多用字典 (2012.2) – sin6
I think we could add sim6 as a variant of sin6, not the other way round.
粵音檢索漢語字典 (2006.12) – sim6
中華新字典 (2007.1) – sim6 (standard), sin6 (variant)
商務新詞典 (2008.1) – sim6
中文新多用字典 (2012.2) – sin6
I think we could add sim6 as a variant of sin6, not the other way round.