I said earlier it's not an easy job and this has been a hard call I can tell you.
Simon the SWEFTA version of HFT has its own set of rules which from a shooter's perspective aren't too hard to grasp, they are just different from UKAHFT and the de facto norm.
Sitting is allowed, prone is not enforced, you can adjust your scope prior to each target and prior to raising the scope to your eye. This means you can always have the option of a reasonably in-focus target and if you are judicious about the plane of focus that you set according to your mark 1 eyeball range estimation, you can also see how far out your guess was. You can use up to 12x mag.
Part of your body must touch the peg or post. Targets are normally in shared lanes, i.e., more than one per peg.
Those I think are the major distinguishing features.
Mr P if one has marked the wrong card or the targets in the wrong order then hopefully the strings have not been reset and the third party could witness that. It may not always be so, I grant you.