Rog
A rubber front line will make it more progressive.
Sponginess may have been the wrong word to choose... it implies lack of control.
There is nothing wrong with an expanding hydraulic hose, as long as it is structurally safe and sound, and gives you the feedback you prefer.
For instance, I like no power assist in my steering systems in my cars because of the feel, yet I prefer it in a larger truck.
That's what I was trying to say. Plus, I like to innovate, save money, and get what I want anyway.... you know.
I have bikes with such good personal setups on the brakes, I wouldn't THINK of installing a steel or kevlar line on them, and other bikes that barely made it home before I had installed braided steel or kevlar lines..and maybe added a caliper and disc......it is very subjective and personal, and I was merely suggesting something that has successfullky worked for me.
Better to have twenty one thousand dollar vehicles than one twenty thousand dollar vehicle, and especially when you can turn a thousand dollar vehicle into a five thousand dollar vehicle.... that's where this old junkyard dog is coming from.
Good luck with it, in any case. Jim