I know exactly that pain! I wish that there was some way for an alert if I'm dropping super drastically.
I'm actually working on reverse engineering the dexcom share api in my free time to create something similar to sugarmate where you can get control of your data and do what you want with it.
But for the time being, have you considered using share2nightscout[0] and grabbing the info into your own control so then you can do the alerting and analysis that you want?
I got a chance to try out the beta bionics artificial pancreas in a research trial and it is a truly new innovation in this field, it lifted about 90% of the constant thinking about bolus and blood sugar from me and allowed me to live my life. It truly deserves all the hype that it is getting.