Never tried any of those, but they should work better than Pi's on-board audio. There are quite a few Pi hats that fit on Pi's 40-pin header, which should probably have better quality than the ones you posted. But if you're fine with any of those, then go with that.

Pi's audio is no good, at least IIRC. You should probably get a DAC for the Pi, there are pleny around, not so expensive.

I won't be on-site either I wish I were, but aparently it's not possible. The workshop will be online, but you'll have to sign up by sending to the email address that's at the top of the page I linked. I guess they will provide a link around those days.

I will give a workshop on Neural Networks in Pd at the PikselXX AI AI AI festival, on the 19th of November, 10-13h Central European Time. The workshop is free of charge, you'll have to book your place though. It will be based on my external [neuralnet] and will cover scenarios where neural networks can be useful in a musical or more broadly, artistic context. More info here https://piksel.no/2022/11/01/pikselxx-ai-ai-ai-workshops

Are you trying to debug it with some debugger? You could also try to put a delay between [loadband] and [; pd dsp 1( and see if that makes a difference. Otherwise you can see if you can turn the DSP on with pdsend and then write a script that does this for you.

@lacuna is correct about [delwrite~]/[delread~] and the DSP loop being dettached, didn't occur to me while writing the post.

First of all, you're using a control delay and not a signal one. You're missing the tilde. Use [delwrite~] instead of [delay]. You'll need a [delread~] to read the signal
Also not that you can't make a feedback connection in the signal domain because it creates a DSP loop. Max probably works under the hood to make this function properly. But if you think, the execution order goes like this: the object that sends audio to its outlet does its computations before the object that receives the audio signal. If you make a feedback connection, which object is supposed to make its computations first?
To achieve this you have to send the output of [cos~] to a [tabsend~] (don't disconnect it from [*~ 0.4]), and connect a [tabreceive~] to [delwrite~]. Also, if you want feedback in your delay, you'll need to do this in the same way, so use another pair of [tabsend~]/[tabreceive~] to connect the output of [delwrite~] back to its input.

"open" here is a message, not an object.

The SOPI groupd had updated [py] to work with Python3 https://github.com/SopiMlab/py

If you want to have a delay shorter than one block size, put the [delwrite~] object in a subpatch, the [delread~] in another subpatch, and connect a dummy outlet of the subpatch with [delwrite~] to a dummy inlet of the subpatch with [delread~].