Let's share some exemples of what can be done with those objects.
I start with an easy phaser.

fatvoice.pd

@Il-pleut All I get is a pop when dsp turns on or off. It is doing something though, it completely kills all other audio in pd if the patch is open. Am I doing something wrong?

@oid It is sending values around 23 to 37 to the [dac~] and saturating it........ with maybe some DC offset.
put a [*~ 0.02] in between and you have a reasonable level.
David.

Yep thank you I didn't notice, I work at low level. Correction done.

And a bunch of somethingizer.

somethingizers.pd

Filters.
I wrote highpass and lowpass but it not that simple.
Low pass is not too bad.

filters.pd

some years ago i tried to create midi data from [expr] bitshift operations: https://forum.pdpatchrepo.info/topic/10797/algorithmic-compositions-from-one-line-of-code
here is another thread: https://forum.pdpatchrepo.info/topic/6277/bitwise-operators-and-syntheis

here i tried something new with ofelia, but i think the same could be done with pd vanilla too. every bpm creates different melody: bitwise_melodygenerator.pd

And a reference in live coding (thank you Darius for this one) :

And to finish the day, 3 fexpr~ loops.
I think they would work just fine with expr.

fexprnew.pd

In this one, you can morph from one preset to another.
They are called keyshape, a reference to a technic used to animate the face of characteres in video game or movies.

fexprkeyshape.pd