Sure, you can build many of these transition type effects manually or with a Combinator, but I really like plugins like this that make it simple to switch between presets in order to quickly hear the difference in transition types to figure out which approach is best for that moment.
It's got 16 different modes and an invert switch that technically makes it 32 different types of transitions.
I own Zynaptiq's Morph, which is better in terms of the morph mode, but this one is pretty good.
It's currently on sale for $23/€19 until the end of September.
https://unitedplugins.com/Transmutator/
MODES
Filter - A high-pass filter is applied to "A" and a low-pass to "B". The transition from 0% to 100% is the frequency of both filters increasing from 20Hz to 20kHz. This makes it sound like the transition is moving upwards. If "Invert" is enabled, then "A" has low-pass and "B" has high-pass, which sounds like the transition is moving downwards.
Spectrum - This uses spectral processing to separate the tonal and noise elements from the inputs. From 0% to 50% the noise from "A" is crossfaded with the noise from "B". So at 50%, you will hear the tone from "A" and the noise from "B". From 50% to 100% the tone from "A" is crossfaded with the tone from "B". In other words, the noise is transitioned first and the tone second, however, if "Invert" is enabled then the tone will be first and then the noise.
Morph - Uses an advanced spectral algorithm to blend the two inputs. The processing is not symmetrical, so "Invert" will flip the signals, which will give a very different result.
Stereo - Splits the inputs into their mid and side components. From 0% to 50% the mid from "A" is crossfaded with the mid from "B". So at 50%, you will hear the side from "A" and the mid form "B". From 50% to 100% the side from "A" is crossfaded with the side from "B". In other words, the mid is transitioned first and the side second, however, if "Invert" is enabled then the side will be first and then the mid.
Pan - Splits the inputs into their left and right components. From 0% to 50% the left from "A" is crossfaded with the left from "B". So at 50%, you will hear the right from "A" and the left form "B". From 50% to 100% the right from "A" is crossfaded with the right from "B". In other words, the left is transitioned first and the right second, however, if "Invert" is enabled then the right will be first and then the left.
Transients - Splits the inputs into their transient and tail components. From 0% to 50% the tail from "A" is crossfaded with the tail from "B". So at 50%, you will hear the transient from "A" and the tail form "B". From 50% to 100% the transient from "A" is crossfaded with the transient from "B". In other words, the tail is transitioned first and the transient second, however, if "Invert" is enabled then the transient will be first and then the tail.
Dynamics - Splits the inputs into their quiet (below the threshold) and loud (above the threshold) components. From 0% to 50% the quiet from "A" is crossfaded with the quiet from "B". So at 50%, you will hear the loud from "A" and the quiet form "B". From 50% to 100% the loud from "A" is crossfaded with the loud from "B". In other words, the quiet is transitioned first and the loud second, however, if "Invert" is enabled then the loud will be first and then the quiet.
Follow - Measures the amplitude shape of both inputs. From 0% to 50% the amplitude information from "B" is applied to "A". So at 50%, you will hear the sound of "A" with the amplitude shape of "B". From 50% to 100% there is a simple crossfade to "B". If "Invert" is enabled then, from 0% to 50% the sound crossfades from "A" to "B" while keeping the amplitude shape from "A". Then from 50% to 100% the amplitude shape is transitioned from "A" to "B".
Liquid - Splits the inputs into 64 spectral bands. From 0% to 50% the odd bands from "A" are crossfaded with the odd bands from "B". So at 50%, you will hear the even bands from "A" and the odd bands form "B". From 50% to 100% the even bands from "A" are crossfaded with the even bands from "B". In other words, the odd bands are transitioned first and the even bands second, however, if "Invert" is enabled then the even bands will be first and then the odd bands.
Multi - Splits the inputs into 6 frequency bands. From 0% to 50% the odd bands from "A" are crossfaded with the odd bands from "B". So at 50%, you will hear the even bands from "A" and the odd bands form "B". From 50% to 100% the even bands from "A" are crossfaded with the even bands from "B". In other words, the odd bands are transitioned first and the even bands second, however, if "Invert" is enabled then the even bands will be first and then the odd bands.
Diffuse - Uses spectral processing to create random variations in each frequency. The transition from 0% to 100% increases the randomness of "A" and decreases for "B". If "Invert" is enabled there is an additional spectral smearing effect added to the randomness.
Wash - Uses reverb to make "A" seem to get further away as "B" gets closer. The transition from 0% to 100% simply increases the reverb for "A" and decreases for "B". If "Invert" is enabled the reverb time will be very short.
Blur - Uses spectral freezing and blurring. The transition from 0% to 100% increases the effect for "A" while decreasing for "B". If "Invert" is enabled the spectral window is much shorter, creating a more artificial effect.
Pitch - Uses pitch shifting to slide up or down by 2 octaves. The transition from 0% to 100% decreases the pitch of "A" from 0 semitones to -24 semitones, while fading to "B" that decreases pitch from +24 semitones to 0 semitones. If "Invert" is enabled the pitches will increase not decrease.
Shift - Uses frequency shifting to slide up or down by 1000Hz. The transition from 0% to 100% decreases the frequency of "A" from 0Hz to -1000Hz, while fading to "B" that decreases frequency from 1000Hz to 0Hz. If "Invert" is enabled the frequency will increase not decrease.
Redux - Uses digital distortion to degrade the audio creatively. The transition from 0% to 100% degrades "A" while fading to "B" that is becoming less degraded. The standard mode uses rate reduction while "Invert" uses a sample and hold effect.