I am not sure if I agree with the cylinder assessment. Seems like the two main cylinders are the ones most people find leaking. Perhaps because they carry the heaviest load. I want to say in all these years and on countess facebook forums it seems to be those two primarily and the other ones are rarely seen leaking. I'd just repair what's broken and in the off-chance once of the other ones starts leaking, get those done then but to each it's own.

I have talked to every owner I know who had the main lifts repaired and not one has had issues with one of the others. Not saying they are bullet proof but why spend the money when it might not be necessary.