Plans for Doc Cochran's character?

It's more down to the show getting cancelled than anything else, but I've always been disappointed that Doc Cochran -- one of the best characters -- was given so little screen-time in the second half of Season 3, even as it was heavily implied he was a "lunger" or had lung cancer. I imagine this would've been elaborated upon in Season 4 (and may well be now in the movie, if it happens); does anybody know what the plans for Cochran were? Has Milch ever talked about this particular character in terms of his intended arc after S3?

It is kind of odd how he's in such bad condition at the end but just kind of slowly disappears from the narrative (the talk with Alma and Sophia after Ellsworth's death being the only really major scene of his I can recall from the latter half of S3).