The Bela runs on 44100 only, so your audio files should play fine, unless you've already tried this on a Bela.

Are there any build instructions for the Pd external? In the GitHub link I can only see instructions on how to build the OF addon.

A bit of shameless self-plug: I built such a looper for chapter 9 of my book "Digital Electronics for Musicians", where overdubbing both forward and backward is possible, without getting distortion. In the 2nd edition of the book, the project is built with a Bela, as a stomp box. here's the chapter's webpage, in case you are interested https://link.springer.com/chapter/10.1007/979-8-8688-0394-9_9 and here's the source code of the first edition https://github.com/Apress/digital-electronics-for-musicians

Aparently, there are no binaries for the architecture of Pi 5, which is different than Pi 3 (and I think 4 too). You can try and get the sources and build it yourself. In deken, go to Edit -> Preferences, and untick "Hide foreign architectures", to get all the results when you search for a package. One of the else packages should contain the sources and instructions on how to build it.

Edit: I couldn't find the sources in deken, so you could try GitHub here https://github.com/porres/pd-else

I don't know at what state Purr-Data is (maintained, developed, abandoned), but you can give PlugData a try instead. It is actively developed, and should probably include what you need. Although, Pd-vanilla should also cover your needs, as almost all externals from the Pd-extended era are present in its repositories, installable through Help->Find externals.

Usually it's very fast, no need to remove prior commits from Pd's repositories. You're sure you supplied a different version number when uploading with deken?

Try the mailing list. All the devs are there, including the LibPd devs/maintainers.

What is this /mrpeach/net prefix? AFAIK, [udpsend] is part of the mrpeach library, so [mrpeach/udpsend] should work. Did you try it?

Perhaps you don't even need [symbol]. You can give the patch a try without it, it might work.

Happy that it worked.