Welcome to the forum !
Can you expand on this?
Not sure what you want expanded.
For more on the 914 filterbank, and it’s uses, see this post, and the video there.
For more on the Fjærlett check out the thread i linked above, or go to that product’s website.
For expansion of other ideas of things to do with a spring reverb, consider adding a predelay before the spring ( which can help allow the initial attack of a sound to be heard clearly before the reverberation begins ) for sounds that aren’t drone type sounds.
( In delay pedals the Behringer VD400 is an analog BBD delay, and the DD400 is a digital delay. There are lots of other places to find delays. )
Another fun thing to do with a spring reverb is to put a tremelo in front of it for a surf guitar sort of effect.