Depending on the quantity of plants. You can top off only, imo.
If you're maintaining the tank cycled by adding ammonia on regular basis. You will still need to remove nitrates with water changes. Or the tank will become an environment for development of all sorts of algae. Most of the time I go red light before acting.
I keep these dirty and well fed in ammonia, with short photo periods. I clean them and do 100% water change before use.
I prefer large rocks as substrate and potted plant because you can see poop and other droppings. You can also remove them to clean or medicate. I Use only 100% inert decor.
Everything has to be easily movable and removable so you can make it bare bottom in minutes...
Think of it as an Emergency Room. Plants and filter integrity could be sacrificed at moment notice.
While maintaining a nice cycled QT environment for new comers.
If you need a hospital tank on very low basis... Not frequently, it's easier to maintain a filter that you can move, ready in an another tank. And crash setup the tank as needed. You can have everything ready.
Just need to add water, move the filter and start the heater.