the challenge I see is speed - the DOS and auto aqua will both take a bit to perform the water change. You can manually trigger with either one. If you want to babysit it - you'll be hanging around the tank for a bit depending on how much water you change at a time.
2 things to watch for - with the DOS solution - that depends pretty heavily on you having the pumps calibrated very close to each other.
The auto aqua - I personally used one to do AWC on a 30 gallon tank - it worked great as the ato & awc for several months - and then one day one of the pumps kicked on and didn't shut off. Luckily I work from home and noticed it - the only way to get it to stop was to unplug the whole auto aqua unit. I could have been an edge case and may be an exception - I removed it from my tank and went back to a different ATO solution.
On our current tank - I drain in to a 32 gallon brute, then that gets pumped to the sink drain with a small pump I dedicated for this purpose. My water storage is in the garage - luckily I have a little portal that goes from the garage to the room with the tanks. I have the pump on my mixing station plugged in to smart plugs that are controlled by alexa - so I grab the hose, put it in the tank - and yell "hey alexa, turn on water pump 2" - and the water starts flowing. A shout to alexa to stop water pump 2 makes it stop. I close a valve, coil up the hose and it stays tucked away for next time.