Just a quick suggestion before I'm off to bed (and forget to post it tomorrow), can you collect leaves and add it to the run? You'd have to collect a lot. 😆 But, it can help with a muddy area.
This one? https://www.backyardchickens.com/threads/revamping-run-in-need-of-ideas.1475033/
I tried to find it, but you've got a lot of threads. 😉
I used panels initially for my run and we secured the panels with t posts. It worked well enough, but I couldn't get my husband to help me figure...
I think metal is harder to work with, extreme temperatures could be a factor, and ducks exude a lot of moisture and metal could rust. Do you have photos of your set up in another thread? Have you considered a hoop coop?