no, that does not work.
the krpano api filters are applied first and you cant unblur them with blur=0 using the css filters
krpano itself does not support hotspot[abc].blur values, this is a zfilter thing on top of krpano.

a) krpano api webgl filters
they are applied on the panorama before or after the hotspots are drawn.
this is what phase is used for.
these filters are applied by webgl and work only on renderer=webgl hotspots
layers are never webgl, so they cant get filters this way

b) zfilter css filters
they are applied later, after phase 2, totally separate from krpano (not a krpano feature)
these filters are applied by css and work (only) on renderer=css3d hotspots and layers.

the simple solution is to blur the pano including all hotspots
(maybe hide / fade out unwanted layers)
and use a layer button (not a hotspot) to return to normal.
but if that works depends on your concept, what you want to do

hmm.. after thinking... try this...
use renderer=webgl (default) on all your hotspots
and renderer=css3d on you non-blur hotspots
non-webvr this should work

Quoted from "Suso Barral"

Is automatic transition between panoramas possible with Zfilter?
Best.

Hi Suso, I'm not sure if I understand 100% ...

All zFilter attributes stay active during the transition between panoramas.
eg. if blur or saturation is active it affects the new panorama as well.
Also you can tween zFilter attributes like any other krpano attribute.
this would also work during a transition.

best, Index

Quoted from "Suso Barral"

I mean, if I can make an automatic presentation with several panoramas with Zfiler transitions, with a timer that regulates the change from scene to scene
Best.

yes of course, you simply start tweens when you call loadscene
the timer / logic how to start the tweens has nothing to do with zFilter, that is base krpano functionality