Rose Lemberg has a really very good article about Bothari and the way Bujold handles disability in the Vorkosiverse (I'm not sure that 'early' strictly applies given they also talk about Mark).
However, the essay is discussing Bothari, and his arc includes a lot of very unpleasant, if not outright disturbing stuff, so trigger warnings are provided for
- Ableism
- Abuse
- Child sexual abuse
- Mental health issues
- Rape/sexual assault
- Shaming
It's very thought provoking, and I'd personally have added the artificial way Bujold lumbers Miles with a seizure disorder just at the point his fracture disorder is rendered no longer quite as limiting via bone replacements. Good writing should make disability incidental to the plot, not blatantly pitch in another layer in order to retain your character's unique selling point.
The article can be found here.