When I get a chance I will post my interview with umpire regarding his thoughts regarding Electronic Line Calling on clay, it is in my archvies somewhere, I have posted at TF here before, Personally speaking there are too many variables on clay, different clay courts, bounces etc, it is also my understanding once a call is made by the ELC a umpire cannot over rule on clay, if the ELO is incorrect. ( I did this interview for an American tennis website tennis.now) also I did one with a lines person on the same subject
Lines people will become a thing of the past when ELC comes in, so how are people going to get their umpires badges in the future, because being a lines person, say for awhile is the first step to become a umpire?
To say that claycourt line judging must continue solely for someone to become an umpire begs the issue; the majority of tournaments are played on HC these days, where automated line judging has already been implemented, and as I understand it, it has already been implemented on grass tournaments too.
So clearly, another way to train future umpires has to happen.
I'm not always thrilled when humans are replaced by machinery/technology; unfortunately this has been going on since the start of the industrial revolution. See many elevator attendants these days?
It has been already widely discussed that human line calling on red clay courts is far from flawless or automatically reliable. Even deciding on which is the specific mark, if the ball skidded somewhat, or if the chair deigns to even get out of the chair if he/she thinks it's clearly proven when the understandably biased player looking at the mark screams "come see how you are wrong!!", or if a crazy bounce derives from more than hitting a line, etc, etc. are what devolves into some of arguments that bog down a match on the terre bateurre.
So IMO the player will probably reconcile themselves to a automatic line calling on claycourts simply because there will be a consistent standard applied for every point. They used it in Madrid Masters already, no? Again, nobody claims that any system implemented will be 100 % reliable or accurate.