Are there any advancement rules for increasing Special Skills you already have through meeting your XP threshold?
I realise it’s not clear enough in how advancement is phrased, but I’ve always run it that any time you advance special skills, that’s two points in those, rather than just two points in a new skill
tbh I’ve also seen people using the Troika! method which is that skills you succeed at give you a chance to increase their value during downtime