Bicycle Mechanics - Short cage campy with 13-29 cassette

After much deliberation about the aesthetic quality of the medium cage on a campy record rear derailleur, I decided to go ahead and hook up a short cage. I replaced the medium with short and got a hook up on the part from my LBS, so it wasn't that painful at all. In fact, the install was really, really straightforward and the derailleur is sitting happily on the frame as I type. Now, let's say, hypothetically, that I might end up running that 13-29 cassette that Campy says requires a medium cage but many a person here has said does not. How might I go about sizing up my chain to reduce the risk of jacking stuff up? I imagine that my trusted usual method won't work, given the range of the cassette? Any suggestions about this would be great.

After much deliberation about the aesthetic quality of the medium cage on a campy record rear derailleur, I decided to go ahead and hook up a short cage. I replaced the medium with short.....That's certainly shallow.......But size it big/big without going thru the derailer.Pull tight till chain and cut end overlap then add 1".

Yes, it's shallow, but that's the way I am with bikes. People, not as much, but bikes, yes.

So, basically don't change the rule of thumb, in spite of the larger cassette cogs?

Yes, it's shallow, but that's the way I am with bikes. People, not as much, but bikes, yes.

So, basically don't change the rule of thumb, in spite of the larger cassette cogs?I have no idea of what your 'rule of thumb was'. Some wouldn't work. I gave you the one that does and isn't a function of cage length and correct application.

Same rule of thumb you used, man.