I think the thing is with multi in/thru links is not the cable length as each thru is buffered, so each device only sees the one cable, as it were. But with data fall/rise errors, as to maintain fast through rates the thru data is not reconstructed but merely passed on via a buffer circuit. so multiple chaining could cause a corruption of the midi data.
I also think the maximum single length midi cable run specified is 15meters 30 odd feet.
Of course the only way to find out is to try it, and I bet unless you start to get silly, chaining multiple units with really long midi leads, it’ll work fine.