Anyway the Philippine style devotional foot nailing has been around long enough, and documented well enough that we can say it doesn't lead inevitably to crippling damage and/or sepsis etc.
Though of course being a religious rite ... taking a certain amount of risk (& putting skin in the game) to express the sincerity of devotion is part of the game and if there are consequences well then that was God's will...
What's extremely important here of course is that body weight is not tearing at the nail, and indeed a not too sharp nail that is pushed through gradually will allow all sorts of things to slip out of the way.
They are standing straight up and the nail goes through in the same direction.
It would be a very different matter if the feet were nailed against the post and then, the feet were pushing down with the full weight of the body - even if the nails were initially carefully inserted while say someone was supporting the victim's body, as soon as you'd let go ... such thin diameter nails, once body weight is put upon them, would begin pressing and crushing and finally tearing upward through tissue in a rather ghastly way.
Now if you wanted to write a scenario for a story with a reversible/survivable crucifixion that still used nails,
the way to go would be, to describe a scene where the victim was first roped up,
and allowed to struggle a bit, so that her weight settled in fully into support by the coils of rope.
It would be necessary that the feet are secured quite firmly, not allowing any significant movement.
Then the crucifier could carefully put in nails similar to this. Then even if the feet are placed against the upright post,
so long as the nails are not a load-bearing part of the crux, permanent damage wouldn't be a predetermined fate,
because there's no weight on them. The nails would then be more of a ritualistic statement & experience,
than the primary means of fixing the victim to the cross.
(Disclaimer ofc don't go nailing, don't do anything that's dumb as a bag of hammers, I'm describing something for a 'realistic' story setting not the next session)
Of course the risk would be, slippage of the ropes so that weight would be transferred onto the nails.
Or too much felxibility in the fixation. Apart from usual concerns about circulation etc.
So you would need someone who really knows his rigging...
As for infection risk, again ... if you are putting in a decent effort to keep things clean, you aren't condemned to it.
Some old school medical procedures involve people having e.g. nails through their heelbones for weeks (been there done that) and they are not necessarily kept in a clean-room and disinfected multiple times per day...
