I'm not sure who I originally got this merc window from but I love it. I decided to update it for VOA. Who knows, the original author may fix it too, but I wanted to put it out there. I forgot what compilation / folder / set it came from so if it's yours just let me know I'll link and give credit where credit is due. I love this window and have used it since I found it. Be sure to zone after you load this UI piece, I noticed the stance list and switch list didn't show up until I did which made editing this window quite tedious. It's done now, I think it looks great. It has tabs which make it bigger than the original but it's fully functional with the new merc options.
I noticed the old version still works, so you only really need this one if you don't want a red UI error, or are actually going to buy merc slots from the marketplace. Anyway, enjoy!