I know your questions didn't have to do with Mclaren. What I notice is that this sounds like something he might say.

I think your question is difficult to answer because there are really other questions behind it. Can anyone really answer the question of when the development of doctrine stopped? I guess we have to ask what is doctrine?? Isn't it an interpretation from the Word of God that is taught?? That's why I think the real questions are what is right and what is wrong because theologies/teachings/doctrines are going to come in each generation. (My opinion is that there are a LOT of wrong ones out there in the last few generations).

Here's some recent doctrines (which may not even be biblical)
What about dispensationalism? Didn't that just coming into being about 100 years ago? (please correct me if I'm wrong). Now I'm not sure if dispensationalism is a correct interpretation or not, but this is a pretty recent development of end times thinking right?? How about liberal theology - that too is pretty recent (but doesn't square with Scripture). How about the New Perspective on Paul?

I guess I look at this whole issue another way. That God used his people at the right times to clarify what His Word already says to stand clear in the midst of error. While I am open to reading someone's new ideas, usually something "new" is something wrong and some "new" false teaching/doctrine instead. And that discernment comes without knowing all the details of the authors from the Reformation era.

I would be interested in reading the books that were recommended here. I really think digging into history reveals a lot of answers to these kinds of questions. At least it does for me.