csSpectral is not well supported by the dev, AFAIK.
The go-to trio is arguably Moebius Lab (standalone only, but can host external AUv3), apeDelay and sparkle (both have AUv3 and standalone).
Moebius Lab by amazing noises is a great one with: spectral brickwall filter, spectral delay, spectral s&h (‘grip’), spectral reverb (‘blur’), and a spectral decimator.
apesoft apeDelay is primarily a spectral delay + spectral brick wall filter, but it also has spectral decimator, blur, noise gate, granular and freeze capabilities (with limited controls.)
apesoft Sparkle does cross synthesis.
Another more limited but really fun option is the burns audio port of MI Clouds, (called ‘granular’, a part of the free Spectrum bundle). In spectral mode it does spectral stretching.