Interesting.......

Instead of a conventional mineral oil, I'd suggest using a dry type graphite based lubricant between the springs.
I've used this in the past with heavy duty steel-on-steel applications (rollingstock).

Molykote I think it was called.
Went on wet, took a couple hours to dry & lasted for years.

Also - I know this sounds dodgy, but I wonder how well it'd work if you re-assembled your spring pack with a thin coating of some form of silicone sealant type product between the leaves?????
Would offer the same dampening characteristics as a neoprene type substance & should last well providing you chose the right product???