I had wondered if Pawns and Symbols was meant to tie into Ford's version of the Klingons, but didn't know for sure.
No, definitely not. It was before inter-novel continuity really existed yet, except between successive works by the same author. As far as I recall, nothing prior to Dwellers in the Crucible
referenced Ford's Klingons.
That's actually the same list I had compiled myself as well, except I didn't have Shadow Lord or Uhura's Song. However the list I compiled contains The Abode of Life, Chain of Attack, and The Final Nexus. Ingrit Thompson appears at least in the final book of that trilogy.
Ah, okay, I was wondering if those three fit in. Though it's a reach to call them a trilogy, since the latter two books were quite a few years later, by a different author, and only a loose followup to Abode