Roel
That SMART guy.
Read the manual... 
You can use the eff. in a different way. Normally you have a eff send for each channel, the effects return is handled as a normal input.
You can also use the effects as an insert. This means, your it is inserted in the signal flow, and all of the signal of your track (only for playback, or recording to another track) or input (for recording, or when using it as a mixer) go through the eff processor.
It's an allround eff. processor in the box. Very usefull... You can patch it any way you'd want. (Can't think of another way... As with a normal mixer, you use it as inserts or on aux...)
So, to answer your questions, you can add effects while recording, or after. And you can add eff to differen tracks at the same time. Also, one eff board has 2 processors on it. (2nd one is limited, some algorithms are only on 1st.) So, with 2 boards, you have 4 stereo eff processors in it...
You can use the eff. in a different way. Normally you have a eff send for each channel, the effects return is handled as a normal input.
You can also use the effects as an insert. This means, your it is inserted in the signal flow, and all of the signal of your track (only for playback, or recording to another track) or input (for recording, or when using it as a mixer) go through the eff processor.
It's an allround eff. processor in the box. Very usefull... You can patch it any way you'd want. (Can't think of another way... As with a normal mixer, you use it as inserts or on aux...)
So, to answer your questions, you can add effects while recording, or after. And you can add eff to differen tracks at the same time. Also, one eff board has 2 processors on it. (2nd one is limited, some algorithms are only on 1st.) So, with 2 boards, you have 4 stereo eff processors in it...