Oh for heaven’s sake. You say they are “hard working” – they certainly are working hard to twist meanings of words. If only they were that willing to work hard on a compromise.
I find it hard to believe that replacing one glass panel will in fact meet safety concerns; will the rise in the floor level be “ramped” to the present level so the existing panels still fulfill their safety function? (I imagining someone leaning across from the raised floor level to enable themselves to get over the lower barrier. I’m imagining a child doing this and falling to their death and your OC being sued….)
The underlined part of your post boils down to “you so tom-ay-to; we say tom-a-toe” – they don’t think it’s an aesthetic issue. Surely that’s in the eyes of the beholding owner!
As previously suggested, file the papers for mediation. Hopefully everyone will come to their senses that $2000 is a small price to pay to avoid thousands in legal fees and time wasted.
And go back to the books looking for those tile cases. They are exactly on point.
Good luck.