I don’t remember whose recordings each was, but as it stands here’s what I’ve implemented:
As Chewie runs off on Pasaana, two KoR say, “Solo’s Wookiee,” and “I get his teeth.” The latter turns his head and it feels like it always was that way.
On Kijimi, the KoR step into frame and the apparent leader says, “Palpatine wants the girl alive. Kill the rest.”
On Exegol, as the KoR step out from around the corner to confront Ben, two say, “Well look who finally made it,” and “Traitor!” The latter is an obvious mirror to Kylo in TFA, highlighting his transformation.
Later, when he pulls the lightsaber out of his ass, a KoR says, “What? How?” And then they all get chopped up, with a few vocalizations that have always been there.
I don’t think these are intrusive, and are 4 out of 6 possible moments for KoR dialogue. (Excluded are “may our bond never again be shattered” during the helmet reforging, and “You betray us for a scavenger” between the other two Exegol lines.)
As far as adding lines, these are the ones that would make sense. I’d love to see them in context, especially if they have effects to match the original vox from the film.