I've lent some workers to the Empire. Some of them had long-term illness, sensory mechanites. After returning, ill pawn with 15 medical skill, enhanced sight and manipulation and slightly below 100% consciousness, self-tend allowed, had 7.6% tend quality.
Such low number in tend quality is wrong. Considering both the ability of mentioned pawn to tend himself and medicine available in the Empire (glitterworld meds).
Thanks for the feedback, I'll add it to the list of things to review. I don't think self tending is really expected to work while visiting another colony but the tend level should at least be better than 7% when returning.