Important seems to me to understand, that the combined load of both springs in the Morgan front suspension sytem are in parallel...as long as the hub touches both springs. In parallel means they are adding their forces, even if it "looks" like they where in a serial mode, but the hub is in between the to springs...which means parallel.
Then, if one of the springs' forces do not touch the hub any longer, usually the rebound spring, this is leading to a sudden massive loss of spring load in total, with all the consequences.
In this article, Peter Ballard explains the interaction very understandable. Just foward to the section where he describes the difference between prallel and serial loads of springs.
https://sites.google.com/site/morganatica/suspension/main-rebound-spring-interation
