Row probability strange behaviour

[XORadmin]

So is this a way to have more than 4 FX on a row? for subsequent rows set PR = 0 and FX4 to some additional effect? Would the extra FX be evaluated in row order, after the last FX on the non-PR0 row?

I don't necessarily think that would be super useful but good to file it away just in case

I don't know what you mean exactly? There is only as many FX in a track row available than the tracktype and in this case for a modular track these are 4.
The discussion here is about the probability setting for a whole row.