I don't think the problem for HFT, for you, is just that the odd prone only shots may not be easily shot kneeling due to obstacles in the way of the target from the kneeling position.
The prone position, especially the HFT style prone position, is quite stable on hold. So HFT courses have lots of small and very small kill sizes. It would be very difficult for an established shooter to try and get a decent score not shooting prone and taking all shots kneeling and standing. So, with respect to you and your wife, you may find it very difficult knocking many down on a decent HFT course shooting mainly kneeling.
So I think FT is probably going to interest you more if you can't shoot prone.
It's a shame though if you don't get to experience HFT. It's a great sport and the people make it.
Is it not possible for you to experiment with prone with a rubber or foam ring around your bag to see if you are comfortable with that? I'm sure most HFT marshalls would be fine with that ( official confirmation would be from Scooby or Sparky on here ).
You and yours will enjoy HFT or FT. It's just a shame if you don't give HFT a chance. You can do both.
Good luck and enjoy.
Last edited by skires; 19th November 2015 at 08:05 AM.