I only mentioned mannitol because it is what is typically used when titrating boric acid. Boric acid combines with glycerol which is also used for the purpose mentioned. The only restriction that I know of is that the OH groups must be on adjacent carbon atoms. Of course this is always true with glycols.
The carbon backbone can be either aliphatic or aromatic an example of the latter is catechol. In the case of catchol the developing capability is effectively destroyed by the formation of the borate ester. The only change in a borate buffer system would be the pH with the addition of the glycol.