To be honest, i think Toy Foxy is what lead William to make the Funtime line, Mangle could easily inspired Willian on the suit design, after all Toy Foxy is supposed to be less scary for the kids, thus the white and pink colors, lipstick and the whole "fun!" thing on the posters, the whole Funtime line is probably based on this "cuter" desing choice since it kinda worked in the past, Mangle is mangled because children loved to play with it, and thats the whole point of the FT line
I agree that Toy Foxy / Funtime Foxy 1 is probably a prototype of sorts, both to test child safety in close range, and also design choices.
A lot of theories assume that Toy Foxy being described as a ‘pull apart, put together attraction’ to be purely a made up story in regards to parents asking why it’s a pile of sharp junk on the floor, but if we take the term more seriously, perhaps Toy Foxy’s original body was also more in line with Funtime animatronics, in that it did pull apart easier than other Toys.
This theory of course would lean in to the next logical step in design: The funtime animatronics’ endoskeletons are really, really, really revamped. They’re safer on the inside to be pulled apart, and also safer to transport various things, wheras if the Toy Foxy design was kept, there would possibly be more room in the suits, but not as strong and a single glance inside would keep parents away for a while.
