Due to NDAs I can't write too much about this but there is a lot of work being done on this front right now and I expect a new generation of these devices to be out for trial in the relatively near future. Pumps are getting smaller, which is one factor that helps and analysis is getting more accurate. Reliability and sensors are improving. But the timing aspect is critical especially without knowledge about environmental factors and the relatively long hysteresis of the feedback is a major obstacle to the big leap forward. Key here is that the body has more data about the situation than an outside device will ever have and that regulation in the body is a fairly global affair [1] so it can act faster and with more precision than you can ever do from a single site. These are all super tricky problems. But compared to the situation only a decade ago it is already much better and I fully expect at least one more round of breakthrough devices. Best of luck there, it's harsh to be a kid with such a demon on your shoulders.

[1] for instance: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4214828/