You are going to kill the battery very quickly doing that, in fact you probably have already damaged it, but not to the point its trash. You probably have taken a couple % of the capacity from the battery in those few discharges. 12.3 is the lowest you should take it, and thats a 50% discharge, but some say 70 to 80% is okay for agm.
There are some who say the total amp hours you will get out of it is the same at a 70% discharge as a 50%. ie 500 cycles pulling 50 amps gives you 25,000 ah's or 70 amps at 350 cycles is also about 25,000 ah's ( based a 100 amp battery ). You should also not use volts as the level of discharge, as it will read higher when fresh off the charger, and it will recover some after a load is taken off of it. Ideally it should rest for 12 to 24 hours to give a true state of charge based on voltage. Buy the ali battery monitor from amazon for 42 bucks, and see the actual discharge in %, not voltage.
11 volts is is a 100 % discharge.
https://www.energymatters.com.au/components/battery-voltage-discharge/