Yes, if this tank is intended to house new fish acquisitions for a couple weeks. I maintain a 20g with spare plants and tons of snails (in spite of my never adding fish food, they find something to eat, and it isn't the plants
). New fish that are questionable [I base this on where I got them] go in this tank for a couple weeks or longer. Ich is very common on fish and usually this is all one has to deal with, and it is easy to treat it in a small tank even with plants.
There is also the benefit of the plants using up ammonia and such, so you never have to worry about mini-cycles. And, the water parameters in this tank will likely be much closer to your main planted tanks so when the time comes to move the new fish, they will not have more stress beyond just being netted once. In my view, maintaining new fish in some sort of pristine bare tank is providing much more stress, not just from the bareness but the likely-different water params, and you are more likely to see ich as a result--after all, ich only occurs from stress.