Make a rule
The BFTA Rules are being changed this year to allow the use of a kneeling roll too (it's optional for BFTA events).
So if you use your bag in a way that is deemed as cheating, that option will still be available ?
Instead of debating rules with different get out Clauses , why not just make a solid rule and be done with it ?
About as much use at field target , as a life guard at the Olympic swimming pool.