I picked up Van Richten's Guide to Ravenloft and have been reading it cover to cover. This is my review of the book, chapter by chapter. Chapter 3 covers over 30 domains, so I'm posting about it as I work my way through the different domains.
The section on Borca is, in spirit, everything I'd wanted the section on Barovia to be. It provides a resourceful Dungeon Master with all the components required to build up a particular kind of adventure. You get just enough information about the key figures within Borca, and with that information you can take any urban adventure you have in mind and run it in Borca.
The land of Borca is pretty generic. The interesting parts are within cities, and those cities are governed by a selection of nobility. Each family is described briefly in this section, and each of them control specific aspects of the domain. They're a little like factions, really, and I can imagine player characters joining them or fighting them (or both) during the course of an adventure. You get the feeling that the time period is maybe Victorian-ish, but there's a lot of flexibility there, I think.
Outside the cities dwell, I guess, peasants. The common folk don't really matter much within this domain, so you can either play up the squalor of the soulless masses, or ignore it entirely and have player characters rub elbows with just the upper class.
Any city setting will do. I can easily see running Rogues in Remballo or certainly anything out of The Blight setting here in Borca.
Borca has two darklords: Ivana Boritsi and Ivan Dilisnya. Originally, they each had their own domain, but kept in touch (presumably through letters delivered by ravens.) Ivana's was Borca, and Ivan's was Dovinia, but the two got combined by the Dark Powers, and the cousins Ivana and Ivan were forced to share. This book doesn't go into that backstory (see Secrets of the dread realms for more) but the end result is the same. The two darklords both dwell in Borca, each living tortured lives as murderous nobles.
Neither get stat blocks, but the spy and noble stat blocks are suggested for Ivana and Ivan, respectively. In this case, it makes sense that they don't have stats, to be honest. Neither are fighters. In fact they're both poisoners, and in addition to the poisons in Dungeon Master's Guide (DMG), there are some new poisons and abilities provided in this section. The power of Ivana and Ivan lies in the high society of Borca, and the loyalty of their fans. It's not hard to imagine masses of oppressed peasants vehemently defending the good names and god-given wealth of the eternally youthful Ivana (she doesn't look a day over 18) or the decrepit Ivan (newly groteque for 5e.)
Speaking of gods, the domains of dread do have a goddess called Ezra. She transcends the mists, so she's not by any means specific to Borca although there's a prominent cathedral in her honour here.
Not to compare this chapter with Starfinder's Pact Worlds source book again, but the way the domains of dread are being presented, so far, is exactly the way I felt the Pact Worlds should have summarized each planet. At the start of each section, there's a standardized listing for the darklords of the domain, the horror genres that the domain is best suited for, hallmark plot devices, and mist talismans you can use to get your player characters to the domain through the mists. I very much appreciate the explicit intent. For instance, Borca is considered a Gothic horror or psychological horror setting.
Borca is a domain of social intrigue. It's potentially the perfect setting for a short urban adventure, or for a one-shot with players who thrive less on combat than on roleplay, mystery, and politics. It frankly surprised me how much I enjoyed this section, because nothing about it particularly leaps out as being unique. It's pretty standard nobility drama set in a bland and ill-defined city, but I guess that's actually its strength. It probably doesn't "need" to be a domain of dread the way Barovia and Bluetspur want to be, but it's a nice setting for your next murder mystery, whether that happens in Ravenloft or the Forgotten Realms or the Lost Lands or Golarion.