didn't Dan manage a Pd "port" with his pdparty?

No. PdParty uses libpd and emulates the GUI objects via send/receives. There is no ability to patch, only run patches and scenes which are essentially folders with a specific layout. I could/would consider adding this in the future if/when libpd can properly wrap the various GUI controls. Also, rethinking interface design for mobile-based patching is a non-trivial task. So far I am limiting myself to things I *need* as opposed to things that are *possible*.

PdParty is meant as an alternative to my Linux-based wearable computer using iOS. It’s not a replacement for desktop Pd.

ah, I didn't meant a "full" replacement, but just the ability to run already made pd patches. that's how I understood the ios/android versions (e.g. libpd).

in case purr-data turns out to be reliable, would it be a possible idea to use it also with this project, or is it too much too fast?

I have no plans to switch from libpd which is built around Pd vanilla. AFAICT most of the major updates to versions/branches/forks etc of Pure Data involve usability and bundling of externals which is a different domain that is not useful for a libpd-based app which creates it’s own interface and only uses the pd core.

something I don't know about, is it (theoretically, if legally) possible to adapt externals so that they run with libpd?

also, does it mean that the core libpd is the same in both android and ios, or did you need to adapt libpd for pdparty? or, you just programmed everything around libpd, but left libpd as it is?

Best,

Joao