Oops, sorry. My bad. I remembered ExecFTPs had all the modules as individual files.
The problem in replacing embedded modules is the size. The module's internal references don't matter as the module is still "loaded" despite being embedded and the data needed for it's placement in the IOP is also in the module. The module can be placed anywhere in the normal memory and then loaded from there and the system takes care that everything is in place after that.
--- Signatures are just lame excuse to waste bandwidth ---