There is no such thing as a disabled shooter. There are some shooters with disabilities.
On the matter of discussing rule changes at an EGM; I'm not up to speed on the BFTA constitution, however it is normal practice for an EGM - whch means extraordinary general meeting - to have only ONE item on the agenda. It is an "extra"-ordinary meeting because there is something that has to be sorted before the next "ordinary" meeting. It's advisable to limit the use of an EGM, to prevent hi-*******; otherwise an EGM can be called for what is apparently a good reason, then a number of members with a hidden agenda force a vote on something else.
This is not to say that any such skullduggery exists in our context, just a point of procedure.