I have watched most of the videos you provided links for.
Some insights I found interesting when listening to the speakers:
- Listening to German Dialect (that is what PD occurs to me) spoken with a strong English/American accent and phonetics is something my language circuitry does not expect and does not easily adapt to.
- Listening to a German dialect that intermixes German and English vocabulary freely is also pretty unexpected and not easy to pick up at first. "Family pictures wegschmeissa" or "Ich hab' lacha müssa, because" as occurs in the videos are nice examples for that. Another nice one (opposite direction) I picked up from the Wiki below was "Mischteeks tscheensche". Go figure that one...
It appears to me that concentrating on understanding a dialect you are not used to and at the same time adjusting your ears to intermixed foreign vocabulary and pronouncation is not what we're made for. Hochdeutsch spoken with a same strong English accent is far easier as your brain doesn't seem to need to juggle with two vocabularies at the same time. Obviously, because there is a varying degree of English vocabulary in the language (depending on who is speaking), understanding PD will pretty much also depend on your fluency in both English and German.
After five minutes or so, I got used to it and it was actually pretty easy to understand nearly all of it. I must, however, add that palatine dialect (that is what it occurs to me, mainly) and my own are pretty close, and I consider my command of English as not too bad, so maybe it is easier to grasp, then. I think I got a hit rate of well over 90%. The more "blend" between languages is there, the harder it is to pick up. It's a bit like trying to understand a radio program that is not well tuned in and constantly changes between stations.
I also found the word Grundsau that was used in one of the videos interesting (and got me puzzled for some seconds). That is actually not a German word used for groundhogs (that is what it appears to me, the German word would be Murmeltier) but rather a direct re-translation of ground and hog to German only existing in PD. It would be interesting to know whether there are more such words in PD vocabulary. [Edit: After looking around a bit for other sources, I even found that there is apparently even a PD Wikipedia at https://pdc.wikipedia.org/wiki/Haaptblatt !]
All in all, nice experience, thanks for the interesting question!