I only fit certified after market parts as I am not a fanchised shop.
The aftermarket catalogue does not show FC 150 in the list of engines that any of the GX 160 coils will fit.
All of the modern "Modules" are called modules because the coil is fired by a Hall effect trigger ( Google it ).
For reasons of patient infringements and royality avoidance no two companies use exactly the same chip so I would doubt that any two modules are interchangable.
Before I attempted to swap them over I would want to see an osilliscope trace of the timing curves of both of the engines.
HE might be right but it is an expensive way to find he is wrong.
You see a lot of Chinese coils listed as "fitting" a lot of different engines that they are not correct for
And if you put the same post in multiple places you can expect to get the same replies cut & pasted.