I found an alternative to the nupps that sounds like it should work. I found it here under this listing: Swallowtail in Sea Silk by Poipill.....here's what she did:
I made no changes to the pattern... although I found P5TOG to be impossible to say the least. Instead, I slipped three as if to purl, purled two together and slipped three over the P2TOG. Maybe my needles weren’t pointy enough, meh. In theory, this shouldn’t look any different anyway.
Hope this helps, I sure am going to keep it handy when I finally try that Trellis.
Everyone keep up the good work!!