I'm not sure what you mean here. If you're hoping that empty rows won't display, it's not a rendering issue. For that you just need a datamodel that excludes the empty rows. Since it's a table, the number of columns is fixed, whether data is rendered or not.
There can be problems with
JSF doing annoying things with "unimportant" things like XML comments (treating them as though they are display elements, taking up cell slots), but that can be switched off by a web.xml setting.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.