Dude, go for it - and buy a long-range reader to go with it. You won’t regret it: most convenient implant location you never saw.
You will regret it without the long-range reader though. Caveat emptor 
By the way, if you implant a NeXT and you want a long range HF reader that should work through your foot, the DL533N XL should fit the bill. I haven’t tried it though.