As per manual:
Neighbour machines cannot be assigned to track 1 or 5.
So an thru machine on track 1 + 3 neighbour tracks. Same for track 5 (with 3 neighbour tracks). So yes, you could say 8 effect tracks (2 x 4 in series) in total (with their own LFO and sequencer possibilities), yielding 16 effects. But remember: Thru machines need to be trigged in the sequencer.
With the restrictions of when doing things in realtime (as in a live situation). Creative use of the track machines in different ways, means you can record and ‘write’ some of the effects into the sample (including parameters tied to the fader). And then make those neighbour track free again for sample playback of just those recorded samples (where you then can set LFO´s on top of that ‘written’ stuff).
An toolbox with different tools for different purposes…
Depending on what end-result you´re aiming for, skillfull use of parts (which allow different effects per part) and pattern changes (chains) might even extend it a bit further. Same goes for the Arranger (think pattern lenght, repeats etc)…