With regards to the kneeling I think it should be the proper 3 point kneeling...

Flat foot, knee and toe.

Sitting on a turned foot is a no no but I also think that shooting on a flattened foot is also deemed as being the same. Also using the bean bag to support the shin in this kneeling position is wrong and should not be tolerated.

This is my opinion and not that of the UKAHFT.