Rule: tone sandhi in topolectical dictionaries I'm looking for a rule or a guideline.

Dictionaries dealing with MSM (Modern Standard Mandarin) would never include tone sandhi into their entries, as people are supposed to know the rules and apply them themselves. 你好 is always going to be ni3 hao3; many topolectical dictionaries, though, do not expect the reader to know the rules of tone sandhi, 你好 would become ni2 hao3, for instance. 

Are there any rules or guidelines regarding whether or not to implement tone sandhi rules in topolectical dictionaries?

edit: some topolectical dictionaries will also include original tone to sandhi marks, e.g.: ni3-2 hao3. I'm not sure if there is a preferred standard when dealing with dialects.
I think to include both original tones and sandhi marks would be a preferred way, as the individual characters are very important in Chinese. And also, the dictionary will include a preface or something explaining the sandhi rules and how they mark them.