As long as you know about the manual vs automatic nature of these devices, and can make sure she sets it correctly each time you are good.
The force mode on the Noco is nice, but it's a manual process.
The Noco needs to be manually started each cycle its plugged in/clamped on and set properly.
Id be curious to know in the case of a power outage if the noco returns to last program or just sits there.
The optimate is completely automatic - you just plug it in and walk away and it detects the battery size and determines the correct charging amperage and voltage. It will charge from .5 volt completely automatically without pressing anything.
If she's flattening batts below 10V with regularity you are going to have extremely short battery lifespans.