In providing vernacular versions of proper names I have tended to follow Raoul Manselli, who provides French translations of several processes in his Spirituels et Béguins du Midi. (In the original, Italian version of this book, Spirituali e beghini di Provenza, Manselli provided the Latin text of several processes, and I used his edition wherever possible.)
In some processes I have adjusted the tenses slightly to clarify the distinction between the act of confession and the things being confessed. E.g. where the text says dixit quod quando debuit fieri executio, I occasionally say, "She says that when the execution was supposed to take place." I have not done other cases (e.g. Raimond Déjean), for reasons I explain in the introduction to Raimond's process.
I have tried to keep my formulae more or less consistent. E.g. in verbal processes the opening words in the Latin text are normally more or less the same: The person's name, followed by the town and diocese, followed by sicut per ipsius confessionem factam in iudicio sub anno millesimo trecentesimo [....], mense [....], legitime nobis constat. This formula invites varying translations, but I have attempted to regularize mine and hope I've succeeded.
In other cases, a phrase begs for variant translations through its context. E.g. the words ut dixit sometimes seem to mean nothing more than "he says," but on other occasions one senses that something more on the order of "or so he says" would be more appropriate. Again, frater occasionally seems best rendered by "brother," but at other times clarity seems to require "friar."
To some extent these problems are inherent in any translating venture; yet in this case I suspect there is something more at stake. It is hard to read these processes without feeling that we have happened upon (perhaps intruded upon) a deeply moving human drama. My decision to use the present tense and to render ut dixit into a skeptical "or so he says" probably reflects my desire to reognize as much.