Practice does not mean that whatever you do, even lying down, is zazen. When the restrictions you have do not limit you, this is what we mean by practice....
When you sit, you will sit. When you eat, you will eat.... If you say,”It doesn't matter,” it means that you are making some excuse to do something in your own way with your small mind. It means that you are to some particular thing or way. That is not what we mean when we say, "Just to sit is enough,” or "Whatever you do is zazen.” Of course, everything you do is zazen, but if so, there is no need to say it.